• Title/Summary/Keyword: functional differential system

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EXISTENCE RESULTS FOR BOUNDARY VALUE PROBLEMS OF VOLTERRA-FREDHOLM SYSTEM INVOLVING CAPUTO DERIVATIVE

  • Shakir M. Atshan;Ahmed A. Hamoud
    • Nonlinear Functional Analysis and Applications
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    • v.29 no.2
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    • pp.545-558
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    • 2024
  • In this study, a class of nonlinear boundary fractional Caputo Volterra-Fredholm integro-differential equations (CV-FIDEs) is taken into account. Under specific assumptions about the available data, we firstly demonstrate the existence and uniqueness features of the solution. The Gronwall's inequality, a adequate singular Hölder's inequality, and the fixed point theorem using an a priori estimate procedure. Finally, a case study is provided to highlight the findings.

Identification of Differentially Expressed Genes by Gabapentin in Cultured Dorsal Root Ganglion in a Rat Neuropathic Pain Model

  • Heo, Ji Hye;Lee, Seung Ha;Chang, Kyung Ha;Han, Eun Hye;Lee, Seung Gwan;Choi, Dal Woong;Kim, Suhng Wook
    • Biomolecules & Therapeutics
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    • v.21 no.2
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    • pp.126-131
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    • 2013
  • Neuropathic pain is a chronic pain disorder caused by nervous system lesions as a direct consequence of a lesion or by disease of the portions of the nervous system that normally signal pain. The spinal nerve ligation (SNL) model in rats that reflect some components of clinical pain have played a crucial role in the understanding of neuropathic pain. To investigate the direct effects of gabapentin on differential gene expression in cultured dorsal root ganglion (DRG) cells of SNL model rats, we performed a differential display reverse transcription-polymerase chain reaction analysis with random priming approach using annealing control primer. Genes encoding metallothionein 1a, transforming growth factor-${\beta}1$ and palmitoyl-protein thioesterase-2 were up-regulated in gabapentin-treated DRG cells of SNL model rats. The functional roles of these differentially expressed genes were previously suggested as neuroprotective genes. Further study of these genes is expected to reveal potential targets of gabapentin.

The Pleiotropic Face of CREB Family Transcription Factors

  • Md. Arifur Rahman Chowdhury;Jungeun An;Sangyun Jeong
    • Molecules and Cells
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    • v.46 no.7
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    • pp.399-413
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    • 2023
  • cAMP responsive element-binding protein (CREB) is one of the most intensively studied phosphorylation-dependent transcription factors that provide evolutionarily conserved mechanisms of differential gene expression in vertebrates and invertebrates. Many cellular protein kinases that function downstream of distinct cell surface receptors are responsible for the activation of CREB. Upon functional dimerization of the activated CREB to cis-acting cAMP responsive elements within the promoters of target genes, it facilitates signal-dependent gene expression. From the discovery of CREB, which is ubiquitously expressed, it has been proven to be involved in a variety of cellular processes that include cell proliferation, adaptation, survival, differentiation, and physiology, through the control of target gene expression. In this review, we highlight the essential roles of CREB proteins in the nervous system, the immune system, cancer development, hepatic physiology, and cardiovascular function and further discuss a wide range of CREB-associated diseases and molecular mechanisms underlying the pathogenesis of these diseases.

Dynamic analysis of a functionally graded tapered rotating shaft under thermal load via differential quadrature finite elements method

  • Fethi, Hadjoui;Ahmed, Saimi;Ismail, Bensaid;Abdelhamid, Hadjoui
    • Advances in aircraft and spacecraft science
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    • v.10 no.1
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    • pp.19-49
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    • 2023
  • The present study proposes a theoretical and numerical investigation on the dynamic response behaviour of a functional graded (FG) ceramic-metal tapered rotor shaft system, by the differential quadrature finite elements method (DQFEM) to identify the natural frequencies for modelling and analysis of the structure with suitable validations. The purpose of this paper is to explore the influence of heat gradients on the natural frequency of rotation of FG shafts via three-dimensional solid elements, as well as a theoretical examination using the Timoshenko beam mode, which took into account the gyroscopic effect and rotational inertia. The functionally graded material's distribution is described by two distribution laws: the power law and the exponential law. To simulate varied thermal conditions, radial temperature distributions are obtained using the nonlinear temperature distribution (NLTD) and exponential temperature distribution (ETD) approaches. This work deals with the results of the effect on the fundamental frequencies of different material's laws gradation and temperature gradients distributions. Attempts are conducted to identify adequate explanations for the behaviours based on material characteristics. The effect of taper angle and material distribution on the dynamic behaviour of the FG conical rotor system is discussed.

Permanence of a Three-species Food Chain System with Impulsive Perturbations

  • Baek, Hunki;Lee, Hung-Hwan
    • Kyungpook Mathematical Journal
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    • v.48 no.3
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    • pp.503-514
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    • 2008
  • We investigate a three-species food chain system with Lotka-Volterra functional response and impulsive perturbations. In [23], Zhang and Chen have studied the system. They have given conditions for extinction of lowest-level prey and top predator and considered the local stability of lower-level prey and top predator eradication periodic solution. However, they did not give a condition for permanence, which is one of important facts in population dynamics. In this paper, we establish the condition for permanence of the three-species food chain system with impulsive perturbations. In addition, we give some numerical examples.

High Reliability Rx Power System Design for Military VoIP Phone (군용 VoIP 전화기를 위한 고신뢰성 Rx 전력 시스템 설계)

  • Park, Kyung-Hwa;Park, Hyun-Jeong;Kim, Hyeon-Sung
    • The Journal of the Korea institute of electronic communication sciences
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    • v.15 no.5
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    • pp.857-864
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    • 2020
  • The multi-functional VoIP phone supports the Ethernet protocol in the TIPS(: Tactical IP Switch), which is one of the sub-systems of the tactical information and communication system (TICN). It provides secured voice / video calls in conjunction with VoIP exchanges and supports differential services such as multi-party calls and command functions. In this paper, improving methods have been proposed to reduce power supply defects in the field of multi-functional VoIP phones. The power supply part was improved by applying TVS of the output voltage inlet of the dedicated adapter of the multi-functional VoIP phone, TVS of the PoE module input, adding blocking diodes, and adding DC / DC converters behind the poly-switch. Also, functional and environmental tests were performed to verify the validity of the proposed methods.

Vocal Fold Leukoplakia: Updates in Diagnosis and Management (성대 백반증의 진단과 치료에 대한 최신 지견)

  • Ji, Jeong-Yeon;Kwon, Tack-Kyun
    • Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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    • v.33 no.1
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    • pp.13-19
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    • 2022
  • Vocal fold leukoplakia poses a challenge to otolaryngologists due to its various spectrum of pathologic diagnosis. The degree of dysplasia is associated with malignancy risk and the new 2017 WHO classification system changed from the 3-tier system to a 2-tier system consisting of low and high grades. Infections including candidiasis, cryptococcosis, and tuberculosis should also be included in the differential diagnosis. Efforts have been made to evaluate risks using endoscopic technologies such as narrow band imaging, and surgery is essential for histopathological diagnosis. Regarding management, it is important to make an accurate diagnosis and find a balance between oncologic safety and functional outcome.

An Analysis of the Signal Properties of Japanese MSAS (일본의 MSAS 특성 분석)

  • Choi, Chang-Mook;Ko, Kwang-Soob
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2016.10a
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    • pp.946-947
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    • 2016
  • This paper is for analyzing not only DGNSS navigation signal but also the navigation parameter of MSAS. The sufficient navigation satellites to determine 3-D position based on DGNSS are simultaneously available at MSAS monitering station and the test region of Korean peninsula. It was verified that the carrier to noise signal is stable to maintain the reliable positioning.

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Comparative Analyses of Four Complete Genomes in Pseudomonas amygdali Revealed Differential Adaptation to Hostile Environments and Secretion Systems

  • Jung, Hyejung;Kim, Hong-Seop;Han, Gil;Park, Jungwook;Seo, Young-Su
    • The Plant Pathology Journal
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    • v.38 no.2
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    • pp.167-174
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    • 2022
  • Pseudomonas amygdali is a hemibiotrophic phytopathogen that causes disease in woody and herbaceous plants. Complete genomes of four P. amygdali pathovars were comparatively analyzed to decipher the impact of genomic diversity on host colonization. The pan-genome indicated that 3,928 core genes are conserved among pathovars, while 504-1,009 are unique to specific pathovars. The unique genome contained many mobile elements and exhibited a functional distribution different from the core genome. Genes involved in O-antigen biosynthesis and antimicrobial peptide resistance were significantly enriched for adaptation to hostile environments. While the type III secretion system was distributed in the core genome, unique genomes revealed a different organization of secretion systems as follows: type I in pv. tabaci, type II in pv. japonicus, type IV in pv. morsprunorum, and type VI in pv. lachrymans. These findings provide genetic insight into the dynamic interactions of the bacteria with plant hosts.

Flexural-Torsional Free Vibrations of Circular Strip Foundation with Variable Breadth (변화폭 원호형 띠기초의 휨-비틀림 자유진동)

  • Lee, Byoung-Koo;Park, Kwang-Kyou;Kim, Gwon-Sik;Lee, Seung-Woo
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2005.11a
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    • pp.764-767
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    • 2005
  • This paper deals with the flexural-torsional free vibrations of circular strip foundations with a variable breadth. The breadth of strip foundation varies with the linear functional fashion, which is symmetric about the mid-arc. Differential equations governing free vibrations of such foundations are derived, in which Winkler foundation is considered as the model of elastic soils. Effects of the rotatory and torsional inertias and shear deformation are included in the governing equations. Differential equations are numerically solved to calculate the natural frequencies. In the numerical examples, the free-free end constraint is considered. Effects of the rotatory and torsional inertias and shear parameter on the natural frequencies are reported. Parametric studies between frequency parameters and various system parameters are investigated.

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