• 제목/요약/키워드: chain recurrent

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CHARACTERIZATIONS ON CHAIN RECURRENCES

  • Park, Jong-Suh;Ku, Se-Hyun
    • Bulletin of the Korean Mathematical Society
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    • v.47 no.2
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    • pp.287-293
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    • 2010
  • It is well known that there is a residual subset J of the space of $C^1$-diffeomorphisms on a compact Riemannian manifold M such that the maps f $\mapsto$ chain recurrent set of f and f $\mapsto$ number of chain components of f are continuous on J. In this paper we get the flow version of the above results on diffeomorphisms.

A NOTE ON CHAIN TRANSITIVITY OF LINEAR DYNAMICAL SYSTEMS

  • Namjip Koo;Hyunhee Lee
    • Journal of the Chungcheong Mathematical Society
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    • v.36 no.2
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    • pp.99-105
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    • 2023
  • In this paper we study some topological modes of recurrent sets of linear homeomorphisms of a finite-dimensional topological vector space. More precisely, we show that there are no chain transitive linear homeomorphisms of a finite-dimensional Banach space having the shadowing property. Then, we give examples to illustrate our results.

AVERAGE SHADOWING PROPERTIES ON COMPACT METRIC SPACES

  • Park Jong-Jin;Zhang Yong
    • Communications of the Korean Mathematical Society
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    • v.21 no.2
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    • pp.355-361
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    • 2006
  • We prove that if a continuous surjective map f on a compact metric space X has the average shadowing property, then every point x is chain recurrent. We also show that if a homeomorphism f has more than two fixed points on $S^1$, then f does not satisfy the average shadowing property. Moreover, we construct a homeomorphism on a circle which satisfies the shadowing property but not the average shadowing property. This shows that the converse of the theorem 1.1 in [6] is not true.

Harmonics Analysis of Railroad Systems using Markov Chain (Markov Chain을 이용한 철도계통의 고조파 분석)

  • Song, Hak-Seon;Lee, Seung-Hyuk;Kim, Jin-O;Kim, Hyung-Chul
    • Proceedings of the KIEE Conference
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    • 2005.11b
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    • pp.230-233
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    • 2005
  • This paper proposes power qualify assessment using Markov Chain applied to Ergodic theorem. The Ergodic theorem introduces the state of aperiodic, recurrent, and non-null. The proposed method using Markov Chain presents very well generated harmonic characteristics according to the traction's operation of electric railway system. In case of infinite iteration, the characteristic of Markov Chain that converges on limiting probability Is able to expected harmonic currents posterior transient state. TDD(Total Demand Distortion) is also analyzed in expected current of each harmonic. The TDD for power quality assesment is calculated using Markov Chain theory in the Inceon international airport IAT power system.

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Sentence-Chain Based Seq2seq Model for Corpus Expansion

  • Chung, Euisok;Park, Jeon Gue
    • ETRI Journal
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    • v.39 no.4
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    • pp.455-466
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    • 2017
  • This study focuses on a method for sequential data augmentation in order to alleviate data sparseness problems. Specifically, we present corpus expansion techniques for enhancing the coverage of a language model. Recent recurrent neural network studies show that a seq2seq model can be applied for addressing language generation issues; it has the ability to generate new sentences from given input sentences. We present a method of corpus expansion using a sentence-chain based seq2seq model. For training the seq2seq model, sentence chains are used as triples. The first two sentences in a triple are used for the encoder of the seq2seq model, while the last sentence becomes a target sequence for the decoder. Using only internal resources, evaluation results show an improvement of approximately 7.6% relative perplexity over a baseline language model of Korean text. Additionally, from a comparison with a previous study, the sentence chain approach reduces the size of the training data by 38.4% while generating 1.4-times the number of n-grams with superior performance for English text.

Gemcitabine for the Treatment of Patients with Osteosarcoma

  • Wei, Mei-Yang;Zhuang, Yan-Feng;Wang, Wan-Ming
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.17
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    • pp.7159-7162
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    • 2014
  • Background: Patients with recurrent or refractory osteosarcoma are considered to have a very poor prognosis, and new regimens are needed to improve the prognosis in this setting. Gemcitabine, a nucleoside antimetabolite, is an analog of deoxycytidine which mainly inhibits DNA synthesis through interfering with DNA chain elongation and depleting deoxynucleotide stores, resulting in gemcitabine-induced cell death. Here we performed a systemic analysis to evaluate gemcitabine based chemotherapy as salvage treatment for patients with recurrent or refractory osteosarcoma. Methods: Clinical studies evaluating the impact of gemcitabine based regimens on response and safety for patients with osteosarcoma were identified by using a predefined search strategy. Pooled response rates (RRs) of treatment were calculated. Results: In gemcitabine based regimens, 4 clinical studies which included 66 patients with recurrent or refractory osteosarcoma were considered eligible for inclusion. Systemic analysis suggested that, in all patients, pooled RR was 12.1% (8/66) in gemcitabine based regimens. Major adverse effects were hematologic toxicity, including grade 3 or 4 anemia, leucopenia and thrombocytopenia in gemcitabine based treatment. No treatment related death occurred in gemcitabine based treatment. Conclusion: This systemic analysis suggests that gemcitabine based regimens are associated with mild activity with good tolerability in treating patients with recurrent or refractory osteosarcoma.

Maple Syrup Urine Disease : Longterm Diet Therapy and Treatment of Acute Metabolic Decompensation (단풍당뇨증의 식이요법과 급성대상부전의 치료)

  • Lee, Hong-Jin;Bae, Eun-Joo;Park, Won-Il;Lee, Kyung-Ja
    • Journal of The Korean Society of Inherited Metabolic disease
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    • v.3 no.1
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    • pp.4-14
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    • 2003
  • Maple syrup urine disease or branched chain ketoacidurias caused by a deficiency in activity of the branched-chain ${\alpha}$-keto acid dehydrogenase(BCKD) complex. This metabolic block results in the accumulation of the branched-chain amino acids(BCAAs) leucine, isoleucine and valine, and the corresponding branched chain ${\alpha}$-keto acids (BCKAs). Based on the clinical presentation and biochemical responses to thiamine administration, MSUD patients can be divided into five phenotypes : classic, intermediate, intermittent, thiamine responsive and dihydrolipoyl dehydrogenase(E3)-deficient. Classic MSUD has a neonatal onset of encephalopathy, and is the most severe ad most common form. Variant forms of MSUD generally have the initial symptoms by 2 years of age. The majority of untreated classic patients die within the early months of life from recurrent metabolic crisis and neurologic deterioration. Treatment involves both longterm dietary management and aggressive intervention during acute metabolic decompensation. We report here our experience of longterm diet therapy and treatment of acute metabolic decompensation of a case of classic MSUD.

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Recurrent Familial Furunculosis Associated with Panton-Valentine Leukocidin-Positive Methicillin-Susceptible Staphylococcus aureus ST1

  • Lee, Jin Young;Park, Ji Young;Bae, Il Kwon;Jeong, Seri;Park, Ji Hyun;Jin, Sol
    • Pediatric Infection and Vaccine
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    • v.25 no.2
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    • pp.107-112
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    • 2018
  • Staphylococcus aureus is now a major community-acquired pathogen worldwide, notably associated with skin and soft tissue infections. Staphylococci are present in the form of colonizers or environmental contaminants at home and increase the risk of recurrent infection. We are describing recurrent familial furunculosis caused by Panton-Valentine Leukocidin-positive methicillin susceptible S. aureus ST1 in Korea. An infant, his father and mother had furunculosis due to methicillin-sensitive S. aureus (MSSA) infection with identical susceptibility patterns. ST1 accounted for all 3 isolates and they were confirmed of having agr group I. Both sec and seh were detected in all isolates using polymerase chain reaction (PCR) assays, and all isolates contained Panton-Valentine leukocidin (PVL) genes. Risk factors for the household spread of S. aureus include skin conditions and close physical contact among household members. The relationship between S. aureus colonization of household contacts and the occurrence of S. aureus infection should be studied into more detail.

microRNA Expression Profile in Patients with Stage II Colorectal Cancer: A Turkish Referral Center Study

  • Tanoglu, Alpaslan;Balta, Ahmet Ziya;Berber, Ufuk;Ozdemir, Yavuz;Emirzeoglu, Levent;Sayilir, Abdurrahim;Sucullu, Ilker
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.5
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    • pp.1851-1855
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    • 2015
  • Background: There are increasing data about microRNAs (miRNA) in the literature, providing abundant evidence that they play important roles in pathogenesis and development of colorectal cancer. In this study, we aimed to investigate the miRNA expression profiles in surgically resected specimens of patients with recurrent and non-recurrent colorectal cancer. Materials and Methods: The study population included 40 patients with stage II colorectal cancer (20 patients with recurrent tumors, and 20 sex and age matched patients without recurrence), who underwent curative colectomy between 2004 and 2011 without adjuvant therapy. Expression of 16 miRNAs (miRNA-9, 21, 30d, 31, 106a, 127, 133a, 133b, 135b, 143, 145, 155, 182, 200a, 200c, 362) was verified by quantitative real-time polymerase chain reaction (qRT-PCR) in all resected colon cancer tissue samples and in corresponding normal colonic tissues. Data analyses were carried out using SPSS 15 software. Values were statistically significantly changed in 40 cancer tissues when compared to the corresponding 40 normal colonic tissues (p<0.001). MiR-30d, miR-133a, miR-143, miR-145 and miR-362 expression was statistically significantly downregulated in 40 resected colorectal cancer tissue samples (p<0.001). When we compared subgroups, miRNA expression profiles of 20 recurrent cancer tissues were similar to all 40 cancer tissues. However in 20 non-recurrent cancer tissues, miR-133a expression was not significantly downregulated, moreover miR-133b expression was significantly upregulated (p<0.05). Conclusions: Our study revealed dysregulation of expression of ten miRNAs in Turkish colon cancer patients. These miRNAs may be used as potential biomarkers for early detection, screening and surveillance of colorectal cancer, with functional effects on tumor cell behavior.