• Title/Summary/Keyword: Stability and Consistency

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BIFURCATIONS AND FEEDBACK CONTROL IN AN EXPLOITED PREY-PREDATOR SYSTEM WITH STAGE STRUCTURE FOR PREY

  • Kar, T.K.;Pahari, U.K.
    • Journal of applied mathematics & informatics
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    • v.29 no.5_6
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    • pp.1193-1204
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    • 2011
  • In the present paper we consider a differential-algebraic prey-predator model with stage structure for prey and harvesting of predator species. Stability and instability of the equilibrium points are discussed and it is observed that the model exhibits a singular induced bifurcation when the economic profit is zero. It indicates that the zero economic profit brings impulse, i.e. rapid expansion of the population and the system collapses. For the purpose of stabilizing the system around the positive equilibrium, a state feedback controller is designed. Finally, numerical simulations are given to show the consistency with theoretical analysis.

A Study on Experience of Health Behaviors of the Menopausal Women (폐경기 여성의 건강행위 경험 연구)

  • Park, Sun Young
    • Korean Journal of Adult Nursing
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    • v.19 no.3
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    • pp.483-494
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    • 2007
  • Purpose: The objective of the study is to describe the experience of health care activities of the menopausal women through phenomenological methodology. Methods: Seven menopausal women participated in the study. Open in-depth interviews were used to collect data, and data were analyzed by the phenomenological methods suggested by Colaizzi. Results: The data were separated into 4 categories of uncomfortable life due to physical and emotional change, building consistency in daily life through regulating a routine rhythm, recovering normality, recovering stability, and 8 clusters of themes; securing regularity in daily life, securing availability in daily life, regulating through elimination and diminishment, regulating through supplementation, being patient and control self, expressing self, review the context and exchanging views, expending a world through one's faith. Conclusion: Participants accepted menopause not as a disease but as a natural course of life and realized that menopausal health problems could be naturally settled in general health care activities in daily life.

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Development and Validation of the Resilience Scale for Children in Grade 4 Trough 6(RSC) (아동용 탄력성 척도 개발 및 타당화 : 초등학교 4-6학년용)

  • Ju, Soyoung;Lee, Yanghee
    • Korean Journal of Child Studies
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    • v.28 no.2
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    • pp.91-113
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    • 2007
  • The purpose of this study was to develop the Resilience Scale for Children(RSC) and to evaluate its reliability and validity. The RSC was administered to 482 children in grades 4 through 6. Factor analysis of the 30 item scale demonstrated Cronbach's ${\alpha}=.89$ for internal consistency of total items. The results of the confirmatory factor analysis supported a five-factor structure. Retest stability was acceptable for the five-factors. Tests of the present scale for criterion-related validity compared favorably with Self-Perception Profile for Children (Lee, et al., 1992) and the Stress Coping Behavior Scale for Children (Kim and Kang, 2003) confirming its applicability to elementary school students for assessment of resilience.

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The Study of the Implementation of the Boot System Using CF(Compact Flash) memory card 2. Implementation of the Boot Loader (CF(Compact Flash)메모리 카드를 이용한 부트 시스템 구현에 관한 연구 2. 부트로더의 구현)

  • 이광철;김영길
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.8 no.1
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    • pp.115-122
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    • 2004
  • This paper describe the implementation or the boot loader for the boot system using of memory card. This boot roader consist of the system initialization, CF card checking, CF memory card checking, file system and the program relocator. This boot loader increase the system stability with program consistency checking algorithm in the read phase from the CF memory card. And this system have the compatibility in CF memory card file system, so system manufacturing productivity increase.

The Numerical Study of Flow through Complicated-Channel with the Lattice Boltzmann Equation Method (Lattice Boltzmann Equation 방법을 복잡한 형상의 채널 유동 해석에 적용하기 위한 수치적 연구)

  • Jeong Gl-Ho;Ha Man-Young
    • Journal of the Korean Society of Visualization
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    • v.2 no.1
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    • pp.46-51
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    • 2004
  • This paper deals with the evaluation of several boundary conditions which are commonly used in the lattice Boltzmann equation method. 2-D channel flow(Poiseuille flow) and lid-driven cavity flow was selected as a test problem of this study, because there exist an analytic solution and previous study which could be used for a benchmarking test. It was found that lattice Boltzmann method still needs more considerations of stability and physical consistency, though it could predict the flow patterns both qualitatively and quantitatively.

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The Numerical Study of 2-D incompressible flow with the Lattice Boltzmann Equation method (Lattice Boltzmann Equation 방법을 이용한 2차원 비압축성 유동 해석에 관한 수치적 연구)

  • Jeong, Gi-Ho;Ha, Man-Young
    • Proceedings of the KSME Conference
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    • 2004.04a
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    • pp.1875-1879
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    • 2004
  • This paper deals with the evaluation of several boundary conditions which are commonly used in the lattice Boltzmann equation method. 2-D channel flow(poiseui1le flow) and lid-driven cavity flow was selected as a test problem of this study, because there exist an analytic solution and previous study which could be used for a benchmarking test. It was found that lattice Boltzmann method still needs more considerations of stability and physical consistency, though it could predict the flow patterns both qualitatively and quantitatively.

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Physical Properties of Acetylated Sweet Potato Starches as Affected by Degree of Substitution (치환도가 초산 고구마전분의 물리적 특성에 미치는 영향)

  • Yoo, Byoung-Seung;Lee, Hye-Lin
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.40 no.7
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    • pp.1048-1052
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    • 2011
  • This study examined the flow properties, paste clarity, freeze-thaw stability and gel strength of acetylated sweet potato starch (ASPS) pastes and gels as a function of degree of substitution (DS). ASPS showed high shear-thinning flow behaviors with high Casson yield stress ($\sigma_{oc}$). Consistency index (K), apparent viscosity ($\eta_{a,100}$) and $\sigma_{oc}$ values of ASPS increased with an increase in DS. In the temperature range of $25{\sim}70^{\circ}C$, ASPS followed an Arrhenius temperature relationship. The activation energies (Ea=13.2~14.3 kJ/mol) of the ASPS samples were much lower than that (18.1 kJ/mol) of the native sweet potato starch (SPS). ASPS gels showed better freeze-thaw stability with a significant decrease in syneresis (%) compared to SPS gel. The gel strength values of ASPS were much lower than that of SPS, and significantly decreased with an increase in DS. The clarity of native SPS paste increased after acetylation.

Grease from Korean Bentonites (국산 벤토나이트 그리이스 제조)

  • Tak Jin Moon;Oh Kwan Kwon
    • Journal of the Korean Chemical Society
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    • v.16 no.3
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    • pp.193-199
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    • 1972
  • Bentones from Korean bentonites were first prepared by reacting bentonites with high molecular weight imidazolines. The cation exchange capacity of bentonites was found more than 100meq/100g sample. Greases were then prepared by dispersing bentones into a lubricating oil and milling through a three-roll dispersion mill. Consistency in microscale, oxidation stability (static), water resistance, and wear property of the greases were tested by the ASTM methods, and good experimental results were obtained.

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GafChromic RTQA Film Dosimetry for Laser Beam with Photodynamic Therapy (GafChromic RTQA Film을 이용한 광역학적 치료용 레이저의 선질 측정)

  • Lee, Byung Koo;Lim, Hyun Soo;Kenar, Necla
    • Journal of Biomedical Engineering Research
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    • v.34 no.2
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    • pp.73-79
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    • 2013
  • Purpose: The purposes of this study were to measure the dose distribution of Photodynamic therapy(PDT) laser with 635 nm wavelength using GafChromic film. Method & Result: We made each output 300 J by changing mW and sec using the laser beam radiation mode such as C.W(Continuous Wave) mode, Pulse mode and Burst Pulse mode and measured the does at 0 mm and 5 mm of distance from optic fiber catheter end to the film, and at 5 mm distance by changing the angle of the end of the optic fiber catheter as $0^{\circ}$ and $0.5^{\circ}$. The radiated film was scanned and OD(Optical Density) was compared. And two-dimensional isodose curves were obtained and the consistency of shapes was compared. It was confirmed that there was consistency between optic density and the dose radiated on the film when we radiated GafChromic film by changing distance and angle of 300 J output in each radiation mode coordinating mW and sec. Conclusion: In this study, we could identify the stability according to changes in laser beam modes, changes in output according to distance, changes in uniformity according to angle, and beam profiles using GafChromic film, and we could also get two-dimensional isodose curve. It was found that small change in the distance and angle that is made when optic fiber catheter was contacted on the treatment area did not make big effects on the output of beam and the uniformity of dose, and it was also found that GafChromic film could be utilized for the purpose of QA of PDT laser beam.

Center point prediction using Gaussian elliptic and size component regression using small solution space for object detection

  • Yuantian Xia;Shuhan Lu;Longhe Wang;Lin Li
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.17 no.8
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    • pp.1976-1995
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    • 2023
  • The anchor-free object detector CenterNet regards the object as a center point and predicts it based on the Gaussian circle region. For each object's center point, CenterNet directly regresses the width and height of the objects and finally gets the boundary range of the objects. However, the critical range of the object's center point can not be accurately limited by using the Gaussian circle region to constrain the prediction region, resulting in many low-quality centers' predicted values. In addition, because of the large difference between the width and height of different objects, directly regressing the width and height will make the model difficult to converge and lose the intrinsic relationship between them, thereby reducing the stability and consistency of accuracy. For these problems, we proposed a center point prediction method based on the Gaussian elliptic region and a size component regression method based on the small solution space. First, we constructed a Gaussian ellipse region that can accurately predict the object's center point. Second, we recode the width and height of the objects, which significantly reduces the regression solution space and improves the convergence speed of the model. Finally, we jointly decode the predicted components, enhancing the internal relationship between the size components and improving the accuracy consistency. Experiments show that when using CenterNet as the improved baseline and Hourglass-104 as the backbone, on the MS COCO dataset, our improved model achieved 44.7%, which is 2.6% higher than the baseline.