294 research outputs found
Synchronization of Chaotic Oscillators due to Common Delay Time Modulation
We have found a synchronization behavior between two identical chaotic
systems^M when their delay times are modulated by a common irregular signal. ^M
This phenomenon is demonstrated both in two identical chaotic maps whose
delay times are driven by a common^M chaotic or random signal and in two
identical chaotic oscillators whose delay times are driven by^M a signal of
another chaotic oscillator. We analyze the phenomenon by using^M the Lyapunov
exponents and discuss it in relation with generalized synchronization.^MComment: 5 pages, 4 figures (to be published in PRE
Teatro e ensino da matemática: atividade desenvolvida num curso de formação docente
Anais do II Seminário Seminário Estadual PIBID do Paraná: tecendo saberes / organizado por Dulcyene Maria Ribeiro e Catarina Costa Fernandes — Foz do Iguaçu: Unioeste; Unila, 2014Este trabalho relata uma aula desenvolvida pelas alunas do Curso de Formação de Docentes
do Instituto Estadual de Educação de Londrina com a colaboração dos Bolsistas do Programa
Institucional de Bolsas de Iniciação à Docência – PIBID – Subprojeto de Matemática, para alunos de
primeiro ano do Ensino Fundamental utilizando o teatro como forma de apresentar conteúdos
matemáticos como números, sequência de números, operações básicas como adição, subtração e
conteúdos de língua portuguesa como leitura e escrita de número
Current status of laparoscopic liver resection for hepatocellular carcinoma
Laparoscopic liver resection (LLR) is becoming widely accepted for the treatment of hepatocellular carcinoma (HCC). Laparoscopic left lateral sectionectomy and minor laparoscopic liver resection are now considered standard approaches, especially for tumors located in the anterolateral segments of the liver. Laparoscopic left lateral sectionectomy in adult donors is also gaining acceptance for child liver transplantation in many centers. Major LLRs, including left hepatectomy and right hepatectomy, have been recently attempted. Laparoscopic donor hepatectomy is becoming more popular owing to increasing demand from young living donors who appreciate its minimal invasiveness and excellent cosmetic outcomes. Several centers have performed total laparoscopic donor right hepatectomy in adult-to-adult living donor liver transplantation. Many meta-analyses have shown that LLR is better than open liver resection in terms of short-term outcomes, principally cosmetic outcomes. Although no randomized control trials have compared LLR with open liver resection, the long-term oncologic outcomes were similar for both procedures in recent case-matched studies
Characteristics of a Delayed System with Time-dependent Delay Time
The characteristics of a time-delayed system with time-dependent delay time
is investigated. We demonstrate the nonlinearity characteristics of the
time-delayed system are significantly changed depending on the properties of
time-dependent delay time and especially that the reconstructed phase
trajectory of the system is not collapsed into simple manifold, differently
from the delayed system with fixed delay time. We discuss the possibility of a
phase space reconstruction and its applications.Comment: 4 pages, 6 figures (to be published in Phys. Rev. E
Chaos Synchronization of delayed systems in the presence of delay time modulation
We investigate synchronization in the presence of delay time modulation for
application to communication. We have observed that the robust synchronization
is established by a common delay signal and its threshold is presented using
Lyapunov exponents analysis. The influence of the delay time modulation in
chaotic oscillators is also discussed.Comment: 9 pages, 6 figure
Endoscopic Pancreatic Sphincterotomy: Indications and Complications
Background/Aims: Although a few recent studies have reported the effectiveness of endoscopic pancreatic sphincterotomy (EPST), none has compared physicians' skills and complications resulting from the procedure. Thus, we examined the indications, complications, and safety of EPST performed by a single physician at a single center. Methods: Among 2,313 patients who underwent endoscopic retrograde cholangiopancreatography between January 1996 and March 2008, 46 patients who underwent EPST were included in this retrospective study. We examined the indications, complications, safety, and effectiveness of EPST, as well as the need for a pancreatic drainage procedure and the concomitant application of EPST and endoscopic sphincterotomy (EST). Results: Diagnostic indications for EPST were chronic pancreatitis (26 cases), pancreatic divisum (4 cases), and pancreatic cancer (8 cases). Therapeutic indications for EPST were removal of a pancreaticolith (10 cases), stent insertion for pancreatic duct stenosis (9 cases), nasopancreatic drainage (7 cases), and treatment of sphincter of Oddi dysfunction (1 case). The success rate of EPST was 95.7% (44/46). Acute complications of EPST included five cases (10.9%) of pancreatitis and one of cholangitis (2.2%). EPST with EST did not reduce biliary complications. Endoscopic pancreatic drainage procedures following EPST did not reduce pancreatic complications. Conclusions: EPST showed a low incidence of complications and a high rate of treatment success; thus, EPST is a relatively safe procedure that can be used to treat pancreatic diseases. Pancreatic drainage procedures and additional EST following EPST did not reduce the incidence of procedure-related complications
Low-Dose 3D Rotational Angiography in Measuring the Size of Intracranial Aneurysm: In Vitro Feasibility Study Using Aneurysm Phantom
Purpose Three-dimensional (3D) measurement of intracranial aneurysms is important in planning endovascular treatment, and 3D rotational angiography (RA) is effective in accurate measurement. The purpose of this study was to evaluate the feasibility of low dose 3D RA (5 seconds 0.10 μGy/frame) in measuring an intracranial aneurysm using an in vitro phantom. Materials and Methods We investigated an in vitro 3D phantom of an intracranial aneurysm with 10 acquisitions of 3D RA with a conventional dose (5 seconds 0.36 μGy/frame) and 10 acquisitions with a low-dose (5 seconds 0.10 μGy/frame). 3D size and neck diameters of the aneurysm were measured and compared between the 2 groups (conventional and low-dose) using noninferiority statistics. Results The aneurysm measurements were well-correlated between the 2 readers, and noninferiority in the measurement of aneurysmal size of low-dose 3D RA was demonstrated, as the upper margin of the 1-sided 97.5% confidence interval did not cross the pre-defined noninferiority margin of 0.2 mm by the 2 readers. Conclusion Low-dose (5 seconds 0.10 μGy/frame) cerebral 3D RA is technically feasible and not inferior in in vitro 3D measurement of an intracranial aneurysm. Thus, low-dose 3D RA is promising and needs further evaluation for its clinical utility in the planning of endovascular treatment of an intracranial aneurysm
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