4,989 research outputs found
Delay-Adaptive Compensator for 3-D Space Formation of Multi-Agent Systems with Leaders Actuation
This paper focuses on the control of collective dynamics in large-scale
multi-agent systems (MAS) operating in a 3-D space, with a specific emphasis on
compensating for the influence of an unknown delay affecting the actuated
leaders. The communication graph of the agents is defined on a mesh-grid 2-D
cylindrical surface. We model the agents' collective dynamics by a complex- and
a real-valued reaction-advection-diffusion 2-D partial differential equations
(PDEs) whose states represent the 3-D position coordinates of the agents. The
leader agents on the boundary suffer unknown actuator delay due to the
cumulative computation and information transmission time. We design a
delay-adaptive controller for the 2-D PDE by using PDE backstepping combined
with a Lyapunov functional method, where the latter is employed to design an
update law that generates real-time estimates of the unknown delay.
Capitalizing on our recent result on the control of 1-D parabolic PDEs with
unknown input delay, we use Fourier series expansion to bridge the control of
1-D PDEs to that of 2-D PDEs. To design the update law for the 2-D system, a
new target system is defined to establish the closed-loop local boundedness of
the system trajectories in norm and the regulation of the states to zero
assuming a measurement of the spatially distributed plant's state. We
illustrate the performance of delay-adaptive controller by numerical
simulations
Design of Single-Stage Flyback PFC Converter for LED Driver
A light emitting diode (LED) driver based on single-stage power factor correction (PFC) is presented in this paper. The designed LED driver using flyback topology can achieve power factor correction and constant-current drive LED in boundary conduction mode. The circuit principle is described in detail, the formulas for MOS switch-on time, switching frequency and the main impact factor of power factor are proposed. The experiment results show that the designed LED driver has high power factor, stable output and it can drive the LED with high efficiency
Delay-Adaptive Control of First-order Hyperbolic PIDEs
We develop a delay-adaptive controller for a class of first-order hyperbolic
partial integro-differential equations (PIDEs) with an unknown input delay. By
employing a transport PDE to represent delayed actuator states, the system is
transformed into a transport partial differential equation (PDE) with unknown
propagation speed cascaded with a PIDE. A parameter update law is designed
using a Lyapunov argument and the infinite-dimensional backstepping technique
to establish global stability results. Furthermore, the well-posedness of the
closed-loop system is analyzed. Finally, the effectiveness of the proposed
method was validated through numerical simulation
Effects of Shadowing on Listening Comprehension of Japanese Texts in Advanced Chinese Learners of Japanese: Manipulating Working Memory Capacity
We performed an experiment to examine the effects of shadowing on listening comprehension of texts. We explored whether the effects differ depending on individual differences in working memory capacity compared with listening for advanced Chinese students learning Japanese. The results showed that the shadowing effects on comprehension and memory of texts vary depending on the learner’s working memory capacity. On the one hand, shadowing facilitated memorization of meaning for learners with a large working memory capacity and understanding the situation model was comparable to listening. On the other hand, learners with a small working memory capacity did not experience the effect of promoting semantic memory and shadowing was less likely for comprehension of the situation model than listening. The results of this study suggest that listening comprehension and memory in a second language differ depending on the combination of listening method and working memory capacity
Polymorphisms of CYP1A1 I462V and GSTM1 genotypes and lung cancer susceptibility in Mongolian
Aim: To study the genotype of cytochrome P450 1A1(CYP1A1) I462V and glutathions S-transferase M1( GSTM1) and the relationship of the genetic polymorphism of them with the susceptibility of lung cancer in Mongolia of China. 

Methods: Allele-specific PCR and a multiplex PCR were employed to identify the genotypes of I462V of CYP1A1 and GSTM1 in a case-control study of 210 lung cancer patients with bronchoscopy diagnosis and 210 matched controls free of malignancy.

Results: The frequencies of the variant CYP1A1(Val/Val) genotypes and GSTM1(-) in lung cancer groups were higher than that in control groups (15.24% vs 7.4% and 56.67% vs 40.95% ). The individuals who carried with CYP1A1(Val/Val) or GSTM1(-) genotype had a significantly higher risk of lung cancer, the OR is 2.56 and 1.89 respectively. Stratified histologically the relative risk increased to 2.6 - fold when the patients carried with two valine alleles than the ones carried one valine allele in cases of SCC. GSTM1(-) genotype is the risk factor of SCC (OR=2.39) and AC(OR=2.16). The presence of at least one Val allele of CYP1A1 and GSTM1(-), the risk of lung cancer was increased, the OR was 4.15 for one Val allele and GSTM1(-) and 2.67 for two Val alleles and GSTM1 Considering ages and smoking status, the risk of lung cancer increased when the age less than 50 who carried with CYP1A1 valine (one or two) alleles or the age during the 51 to 65 who carried with GSTM1(-) genotype. The light smokers with CYP1A1 valine alleles and GSTM1(-) have a high risk for lung cancer. No association was found between the light and heavy drinkers with the susceptibility of lung cancer and the genetic polymorphisms of CYP1A1 I462V and GSTM1(-). 

Conclusion: The valine allele of CYP1A1 was the risk factors of lung cancer especially for SCC and GSTM1(-) also was the risk factor of lung cancer and especially for SCC and AC of Mongolian, China. Light smoking has a influence each other with genotype of CYP1A1 I462V and GSTM1(-) and susceptibility of lung cancer. No relationship was found between the susceptibility of lung cancer and drinkers with genetic polymorphisms of CYP1A1 I462V and GSTM1(-). The influence of genotypes on the susceptibility of lung cancer may depend on the ages. There may be a synergetic interaction between CYP1A1 valine allele and GSTM1(-) genotypes on the elevated susceptibility of lung cancer. So do those genotypes with light smokers. Key words polymorphism; genotype; lung cancer; cytochrome P450;glutathione S-transferase Abbreviations: SCC, squamous cell carcinoma; AC, adenocarcinoma; SCLC, small cell lung cancer; LCLC, large cell lung cance
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