• Title/Summary/Keyword: control dependence

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Controlled growth of Carbon Nanotubes using thermal CVD

  • Lee, Tae-Jae;Lyu, Seung-Chul;Choi, Sang-Kyu;Lee, Cheol-Jin;Lee, Jin-Ho
    • 한국정보디스플레이학회:학술대회논문집
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    • 2002.08a
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    • pp.674-677
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    • 2002
  • Vertically aligned CNTs were grown on Fe-deposited $SiO_2$ substrates using thermal CVD of acetylene gas. The size of Fe particle is controlled by the flow rate of $NH_3$ and pretreatment time, which leads to control the diameter of CNTs. As the diameter of CNTs decreases, the growth rate is enhanced with an inverse dependence of the CNT diameter. The growth rate of CNTs increases linearly as the growth time increases until 30 min but is rapidly decreased over 40 min. We found an inverse relation between the diameter and growth rate of carbon nanotubes. As the diameter of CNTs increases, the compartment layers of bamboo-shaped CNTs appear more frequently. A base-growth model is suitable to explain the dependence of growth rate and structure of CNTs on the diameter size of catalytic particles.

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Gate-tunable Supercurrent in Graphene-based Josephson Junction (그래핀 조셉슨 접합에서 초전류의 게이트 전압 의존성)

  • Jeong, D.;Lee, G.H.;Doh, Y.J.;Lee, H.J.
    • Progress in Superconductivity
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    • v.13 no.1
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    • pp.47-51
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    • 2011
  • Mono-atomic-layer graphene is an interesting system for studying the relativistic carrier transport arising from a linear energy-momentum dispersion relation. An easy control of the carrier density in graphene by applying an external gate field makes the system even more useful. In this study, we measured the Josephson current in a device consisting of mono-layer graphene sheet sandwiched between two closely spaced (~300 nm) aluminum superconducting electrodes. Gate dependence of the supercurrent in graphene Josephson junction follows the gate dependence of the normal-state conductance. The gate-tunable and relatively large supercurrent in a graphene Josephson junction would facilitate our understanding on the weak-link behavior in a superconducting-normal metal-superconducting (SNS) type Josephson junction.

Muscle Force Potentiation During Constant Electrical Stimulation - Dependence on Pulse-Amplitude and Pulse-Duration of Electrical Stimulation (일정 전기자극하의 근력 상승 - 전기 자극 파형의 펄스 진폭과 펄스폭에 대한 의존성)

  • Kim, Ji-Won;Kwang, Min-Young;Eom, Gwang-Moon
    • The Transactions of the Korean Institute of Electrical Engineers D
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    • v.55 no.10
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    • pp.458-463
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    • 2006
  • The purpose of this work is to investigate the fundamental properties of the gradual muscle force potentiation. We investigated the dependence of force potentiation on both the pulse-amplitude and the pulse-duration with different ramp-up time. The experimental results showed that the force increment ratio (FIR) during constant electrical stimulation decreased with pulse-amplitude and also with pulse-duration. The FIR was greater with short ramp-up time in both the pulse-amplitude and pulse-width modulation. The feasible mechanism might be that the myosin light chain phosphorylation induces the force potentiation and it occurs only in the fast type muscle fibers which are recruited first. These observations indicate that muscle potentiation must be understood well for the accurate control of muscle force.

Bit-Level Systolic Array for Modular Multiplication (모듈러 곱셈연산을 위한 비트레벨 시스토릭 어레이)

  • 최성욱
    • Proceedings of the Korea Institutes of Information Security and Cryptology Conference
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    • 1995.11a
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    • pp.163-172
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    • 1995
  • In this paper, the bit-level 1-dimensionl systolic array for modular multiplication are designed. First of all, the parallel algorithms and data dependence graphs from Walter's Iwamura's methods based on Montgomery Algorithm for modular multiplication are derived and compared. Since Walter's method has the smaller computational index points in data dependence graph than Iwamura's, it is selected as the base algorithm. By the systematic procedure for systolic array design, four 1-dimensional systolic arrays ale obtained and then are evaluated by various criteria. Modifying the array derived from 〔0,1〕 projection direction by adding a control logic and serializing the communication paths of data A, optimal 1-dimensional systolic array is designed. It has constant I/O channels for modular expandable and is good for fault tolerance due to unidirectional paths. And so, it is suitable for RSA Cryptosystem which deals with the large size and many consecutive message blocks.

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Limonene Inhibits Methamphetamine-Induced Sensitizations via the Regulation of Dopamine Receptor Supersensitivity

  • Gu, Sun Mi;Kim, Sung Yeon;Lamichhane, Santosh;Hong, Jin Tae;Yun, Jaesuk
    • Biomolecules & Therapeutics
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    • v.27 no.4
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    • pp.357-362
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    • 2019
  • Limonene is a cyclic terpene found in citrus essential oils and inhibits methamphetamine- induced locomotor activity. Drug dependence is a severe neuropsychiatric condition that depends in part on changes in neurotransmission and neuroadaptation, induced by exposure to recreational drugs such as morphine and methamphetamine. In this study, we investigated the effects of limonene on the psychological dependence induced by drug abuse. The development of sensitization, dopamine receptor supersensitivity, and conditioned place preferences in rats was measured following administration of limonene (10 or 20 mg/kg) and methamphetamine (1 mg/kg) for 4 days. Limonene inhibits methamphetamine- induced sensitization to locomotor activity. Expression of dopamine receptor supersensitivity induced by apomorphine, a dopamine receptor agonist, was significantly reduced in limonenepretreated rats. However, there was no significant difference in methamphetamine-induced conditioned place preferences between the limonene and control groups. These results suggest that limonene may ameliorate drug addiction-related behaviors by regulating postsynaptic dopamine receptor supersensitivity.

Comparison of Microbial Diversity and Composition in the Jejunum and Colon of Alcohol-Dependent Rats

  • Fan, Yang;Ya-E, Zhao;Ji-dong, Wei;Yu-fan, Lu;Ying, Zhang;Ya-lun, Sun;Meng-Yu, Ma;Rui-ling, Zhang
    • Journal of Microbiology and Biotechnology
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    • v.28 no.11
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    • pp.1883-1895
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    • 2018
  • Alcohol dependence is a global public health problem, yet the mechanisms of alcohol dependence are incompletely understood. The traditional view has been that ethanol alters various neurotransmitters and their receptors in the brain and causes the addiction. However, an increasing amount of experimental evidence suggests that gut microbiota also influence brain functions via gut-to-brain interactions, and may therefore induce the development of alcohol use disorders. In this study, a rat model of alcohol dependence and withdrawal was employed, the gut microbiota composition was analyzed by high-throughput 16S rRNA gene sequencing, and the metagenome function was predicted by PICRUSt software. The results suggested that chronic alcohol consumption did not significantly alter the diversity and richness of gut microbiota in the jejunum and colon, but rather markedly changed the microbiota composition structure in the colon. The phyla Bacteroidetes and eight genera including Bacteroidales S24-7, Ruminococcaceae, Parabacteroides, Butyricimonas, et al were drastically increased, however the genus Lactobacillus and gauvreauii in the colon were significantly decreased in the alcohol dependence group compared with the withdrawal and control groups. The microbial functional prediction analysis revealed that the proportions of amino acid metabolism, polyketide sugar unit biosynthesis and peroxisome were significantly increased in the AD group. This study demonstrated that chronic alcohol consumption has a dramatic effect on the microbiota composition structure in the colon but few effects on the jejunum. Inducement of colonic microbiota dysbiosis due to alcohol abuse seems to be a factor of alcohol dependence, which suggests that modulating colonic microbiota composition might be a potentially new target for treating alcohol addiction.

The Moderating Effects of the Teacher-Child Relationship on the Relationship between Young Children's Self-Control and Behavior Problems (유아의 자기통제력과 행동문제간의 관계에 대한 교사 - 유아관계의 조절효과)

  • Kim, Sun-Hee
    • Korean Journal of Child Studies
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    • v.35 no.3
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    • pp.31-47
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    • 2014
  • This study investigates the moderating effects of the teacher-child relationship on the relationship between young children's self-control and behavior problems. 150 young children aged 3, 4, and 5 and their 40 classroom teachers participated in this study. The results of this investigation reveal the following: (1) Young children's self-control is significantly related to behavior problems. (2) The teacher-child relationship (conflict, dependence, intimacy) is significantly related to young children's behavior problems. (3) The effects of self-control on young children's anxiety and withdrawal behavior are significantly moderated by conflict driven teacher-child relationships. (4) The effects of self-control on young children's aggression and impulsive behavior are significantly moderated by dependent teacher-child relationships.

Active Noise Control Algorithm having Fast Convergence (빠른 수렴성을 갖는 능동 소음제어 알고리즘에 관한 연구)

  • 나희승;박영진
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 1998.04a
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    • pp.670-677
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    • 1998
  • Many of the adaptive noise control systems utilize a form of the least mean square (LMS) algorithm. In the active control of noise, it is common practice to locate an error microphone far from the control source to avoid the near-field effects by evanescent waves. Such a distance between the control source and the error microphone makes a certain level of time-delay inevitable and, hence, may yield undesirable effects on the convergence properties of control algorithms such as filtered-x LMS. This paper discusses the dependence of the convergence rate on the acoustic error path in these popular algorithms and introduces new algorithms which increase the convergence region regardless of the time-delay in the acoustic error path. Performances of the new LMS algorithms are presented in comparison with those by the conventional algorithms based on computer stimulations and experiments.

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Smoking Cessation Treatment and Outcomes in Medium to Heavy Cigarette Smokers being Treated for Cancer in Jordan

  • Hawari, Feras Ibrahim;Obeidat, Nour Ali;Ayub, Hiba Salem;Dawahrah, Sahar Sattam;Hawari, Saif Feras
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.11
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    • pp.6875-6881
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    • 2013
  • Background: Studies evaluating smoking cessation treatment outcomes in cancer patients are scarce, despite smoking cessation importance in cancer care. We sought to add to the literature by evaluating smoking cessation in a challenging group of cancer patients (medium-to-heavy smokers) visiting an out-patient smoking cessation clinic (SCC) in a cancer center in Amman, Jordan. Materials and Methods: Patients smoking >9 cigarettes per day (CPD) and referred to the SCC between June 2009 and May 2012 were studied. Clinic records were reviewed to measure demographic and baseline clinical characteristics, and longitudinal (3-, 6- and 12- month) follow-up by phone/clinic visit was conducted. At each follow-up, patients were asked if they experienced medication side-effects, if they had returned to smoking, and reasons for failing to abstain. Descriptive and multivariable logistic regression analyses were performed. Results: A total of 201 smokers were included in the analysis. The 3-month abstinence was 23.4% and significantly associated with older age, being married, and presenting with lower (${\leq}10ppm$) baseline carbon monoxide (CO) levels. On a multivariable level, lower CO levels, a higher income (relative to the lowest income group), being older, and reporting severe dependence (relative to dependence reported as 'somewhat' or 'not') were significant predictors of higher odds of abstinence at three months. Reasons for failing to quit included not being able to handle withdrawal and seeing no value in quitting. Long-term ARs did not reach 7%. Conclusions: In a sample of Jordanian smokers (>9CPD) with cancer and receiving smoking cessation treatment, ARs were low and further declined with time. Results underscore the need for more aggressive patient management and rigorous follow-up during and after smoking cessation treatment, particularly when this takes place in challenging settings. Observed reasons for failure to abstain should be used to tailor counseling practices.

A Convergence Study on Influencing Factors on the Sleep of University Students -Focusing on the Dependence of Smartphone- (대학생의 수면 관련 요인에 대한 융합 연구 : 스마트폰 의존을 중심으로)

  • Han, Suk-Jung;Chun, Ji-Young
    • Journal of the Korea Convergence Society
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    • v.10 no.12
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    • pp.465-476
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    • 2019
  • This study was convergence study to determine sleep and its factors in university students on the basis of Spielman's 3P model. The participants were 191 graduate and undergraduate students who were scheduled to take the exam after 1~2 weeks. The related variables of quality of sleep were self-control, stress, test anxiety, smartphone dependence, and daytime sleepiness. Chi-square test and t-test were used to make a comparison of the quality of sleep between the good and the bad sleep quality group. Pearson's coefficient correlation analysis was performed for correlation between the quality of sleep and the general characteristics, self-control, stress, test anxiety, smartphone dependence, and daytime sleepiness. Stress and test anxiety as precipitating factors for sleep disturbance, smartphone dependency as a perpetuating factor for sleep disorder, and daytime sleepiness as a sleep-related factor were correlated with the quality of sleep; no statistically significant correlation was found with self-control as a predisposing factor in the biopsychological area. It is necessary to solve such problems with mental health as stress and test anxiety, which are factors for sleep disturbance, and smartphone dependency as a perpetuating factor for sleep disorder, in pursuit of higher quality of sleep for university students.