• 제목/요약/키워드: initial value method

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Combined Non-Thermal Microbial Inactivation Techniques to Enhance the Effectiveness of Starter Cultures for Kimchi Fermentation

  • Su-Ji Kim;Sanghyun Ha;Yun-Mi Dang;Ji Yoon Chang;So Yeong Mun;Ji-Hyoung Ha
    • Journal of Microbiology and Biotechnology
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    • v.34 no.3
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    • pp.622-633
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    • 2024
  • For quality standardization, the application of functional lactic acid bacteria (LAB) as starter cultures for food fermentation is a well-known method in the fermented food industry. This study assessed the effect of adding a non-thermally microbial inactivated starter culture to kimchi, a traditional Korean food, in standardizing its quality. In this study, pretreatment based on sterilization processes, namely, slightly acidic electrolyzed water (SAEW) disinfection and ultraviolet C light-emitting diode (UVC-LED) of raw and subsidiary kimchi materials were used to reduce the initial microorganisms in them, thereby increasing the efficiency and value of the kimchi LAB starter during fermentation. Pretreatment sterilization effectively suppressed microorganisms that threatened the sanitary value and quality of kimchi. In addition, pretreatment based on sterilization effectively reduced the number of initial microbial colonies in kimchi, creating an environment in which kimchi LAB starters could settle or dominate, compared to non-sterilized kimchi. These differences in the initial microbial composition following the sterilization process and the addition of kimchi LAB starters led to differences in the metabolites that positively affect the taste and flavor of kimchi. The combined processing technology used in our study, that is, pre-sterilization and LAB addition, may be a powerful approach for kimchi quality standardization.

The Effect of Liquidity, Leverage, and Profitability on Firm Value: Empirical Evidence from Indonesia

  • JIHADI, M.;VILANTIKA, Elok;HASHEMI, Sayed Momin;ARIFIN, Zainal;BACHTIAR, Yanuar;SHOLICHAH, Fatmawati
    • The Journal of Asian Finance, Economics and Business
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    • v.8 no.3
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    • pp.423-431
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    • 2021
  • This study aims to examine the effect of liquidity, activity, leverage, and profitability on firm value, as well as the effect of disclosure of corporate social responsibility (CSR), which in this study is a moderator and company size as a control variable. The sampling technique used in this study is a purposive sampling method with certain criteria, to obtain a sample of 22 LQ45 index companies listed on the Indonesia Stock Exchange in 2014-2019. The data analysis method in this study used was the Multiple Linear Regression Analysis with the SPSS 18 Program. The results show that the ratios of liquidity, activity, leverage, and profitability are significant to firm value in accordance with the initial hypothesis of the study. Corporate Social Responsibility (CSR) plays a role as a moderating variable and company size variable as a control variable on the effect of financial ratios (liquidity, activity, leverage, and profitability) on firm value. The implication of this research is that CSR has a very important role in increasing company value. To attract more investors, companies must pay attention not only to financial performance but also to social performance. Large-scale companies tend to do more CSR so that the company value will increase.

An Improved Continuous Integral Variable Structure Systems with Prescribed Control Performance for Regulation Controls of Uncertain General Linear Systems (불확실 일반 선형 시스템의 레귤레이션 제어를 위한 사전 제어 성능을 갖는 개선된 연속 적분 가변구조 시스템)

  • Lee, Jung-Hoon
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.66 no.12
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    • pp.1759-1771
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    • 2017
  • In this paper, an improved continuous integral variable structure systems(ICIVSS) with the prescribed control performance is designed for simple regulation controls of uncertain general linear systems. An integral sliding surface with an integral state having a special initial condition is adopted for removing the reaching phase and predetermining the ideal sliding trajectory from a given initial state to the origin in the state space. The ideal sliding dynamics of the integral sliding surface is analytically obtained and the solution of the ideal sliding dynamics can predetermine the ideal sliding trajectory(integral sliding surface) from the given initial state to the origin. Provided that the value of the integral sliding surface is bounded by certain value by means of the continuous input, the norm of the state error to the ideal sliding trajectory is analyzed and obtained in Theorem 1. A corresponding discontinuous control input with the exponential stability is proposed to generate the perfect sliding mode on the every point of the pre-selected sliding surface. For practical applications, the discontinuity of the VSS control input is approximated to be continuous based on the proposed modified fixed boundary layer method. The bounded stability by the continuous input is investigated in Theorem 3. With combining the results of Theorem 1 and Theorem 3, as the prescribed control performance, the pre specification on the error to the ideal sliding trajectory is possible by means of the boundary layer continuous input with the integral sliding surface. The suggested algorithm with the continuous input can provide the effective method to increase the control accuracy within the boundary layer by means of the increase of the $G_1$ gain. Through an illustrative design example and simulation study, the usefulness of the main results is verified.

Characteristic Analysis of the Coefficient of Initial Abstraction and Development of its Formular in the Rural Watersheds - for the Small-Medium Watersheds in the Geum and Sapkyo River - (농촌유역에서의 초기강우손실 특성분석과 계수 산정식 개발 - 금강.삽교천 중소유역을 중심으로-)

  • Kim, Tai-Cheol;Lee, Jeong-Seon
    • Journal of The Korean Society of Agricultural Engineers
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    • v.50 no.6
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    • pp.3-12
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    • 2008
  • It is important to estimate accurate effective rainfall to analyse flood flow and long-term runoff for the rational planning, design, and management of water resource. The initial abstraction is also important to estimate effective rainfall. The Soil Conservation Service (SCS) has developed a procedure and it has been most commonly applied to estimate effective rainfall. But the SCS method still has weak points, because of unnatural assumptions such as antecedent moisture conditions and initial abstraction. The coefficient of initial abstraction(K) is depending on the soil moisture condition and antecedent rainfall. The maximum storage capacity of Umax which is calibrated by stream flow data in the proposed watershed was derived from the DAWAST(DAily WAtershed STreamflow) model. The values of K obtained from 69 storm events at the five watersheds are ranging from 0.133 to 0.365 and its mean value is 0.207. Effective rainfall could be estimated more reasonably by introducing new concept of initial abstraction. The equation of $K=0.076Sa^{0.255}$ was recommended instead of 0.2 and it could be applicable to the small-medium rural watersheds.

A LINEARIZED FINITE-DIFFERENCE SCHEME FOR THE NUMERICAL SOLUTION OF THE NONLINEAR CUBIC SCHRODINGER EQUATION

  • Bratsos, A.G.
    • Journal of applied mathematics & informatics
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    • v.8 no.3
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    • pp.683-691
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    • 2001
  • A linearized finite-difference scheme is used to transform the initial/boundary-value problem associated with the nonlinear Schrodinger equation into a linear algebraic system. This method is developed by replacing the time and the nonlinear term by an appropriate parametric linearized scheme based on Taylor’s expansion. The resulting finite-difference method is analysed for stability and convergence. The results of a number of numerical experiments for the single-soliton wave are given.

ON THE APPLICATION OF MIXED FINITE ELEMENT METHOD FOR A STRONGLY NONLINEAR SECOND-ORDER HYPERBOLIC EQUATION

  • Jiang, Ziwen;Chen, Huanzhen
    • Journal of applied mathematics & informatics
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    • v.5 no.1
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    • pp.23-40
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    • 1998
  • Mixed finite element method is developed to approxi-mate the solution of the initial-boundary value problem for a strongly nonlinear second-order hyperbolic equation in divergence form. Exis-tence and uniqueness of the approximation are proved and optimal-order $L\infty$-in-time $L^2$-in-space a priori error estimates are derived for both the scalar and vector functions approximated by the method.

Inverter Output Voltage Synthesis Using Novel Dead Time Compensation (새로운 데드타임보상법을 이용한 인버터 출력전압의 합성)

  • Choi, Jong-Woo;Sul, Seung-Ki
    • Proceedings of the KIEE Conference
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    • 1994.07a
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    • pp.262-264
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    • 1994
  • In is paper, a novel dead time compensation method is presented which produces inverter output voltages equal to reference voltages. An experimental result is also presented to demonstrate the validity of the proposed method. The reference voltage can be used as a feedback value, which is essential for sensorless vector control and flux estimation. The method can be carried out automatically by an inverter controller for initial set-up without any extra hardware.

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Selection of Cluster Hierarchy Depth and Initial Centroids in Hierarchical Clustering using K-Means Algorithm (K-Means 알고리즘을 이용한 계층적 클러스터링에서 클러스터 계층 깊이와 초기값 선정)

  • Lee, Shin-Won;An, Dong-Un;Chong, Sung-Jong
    • Journal of the Korean Society for information Management
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    • v.21 no.4 s.54
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    • pp.173-185
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    • 2004
  • Fast and high-quality document clustering algorithms play an important role in providing data exploration by organizing large amounts of information into a small number of meaningful clusters. Many papers have shown that the hierarchical clustering method takes good-performance, but is limited because of its quadratic time complexity. In contrast, with a large number of variables, K-means has a time complexity that is linear in the number of documents, but is thought to produce inferior clusters. In this paper, Condor system using K-Means algorithm Compares with regular method that the initial centroids have been established in advance, our method performance has been improved a lot.

A Study on State Estimation Algorithm in Power System Using Inverse Lemma (Inverse Lemma를 이용한 상태추정 알고리즘의 개선에 관한 연구)

  • Moon, Y.H.;Park, J.D.;Park, J.K.
    • Proceedings of the KIEE Conference
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    • 1996.11a
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    • pp.182-185
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    • 1996
  • The purpose of slate estimation in power system is to estimate the best-fit Slate variables from the measurements contaminated by various kind of noise. But because the majority of state estimation modules in EMS lack the convergence characteristics, sometimes the desirable outputs can't be obtained. So, in this paper, the new algorithm using the load now output as initial values in the state estimation calculation is proposed to guarantee the convergence. And if the load now outputs were used as the initial values in the calculation, the change in each step would be small compared to the original method using the flat start point. And the Inverse Lemma is used in the algorithm to calculate the new stale in each iteration step for reducing the calculation time. The proposed algorithm was tested on the IEEE 14, 30, 118 bus systems. Eventually, we were able to verity that the differences between the results obtained by the original method and proposed method were relatively small, and the effectiveness of the proposed algorithm increased when applied to the bigger systems.

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A New Binary Thresholding Method using Bit-plane Information (비트평면 정보를 사용한 새로운 2진 임계화 방법)

  • 김하식;조남형;김윤호;이주신
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.5 no.6
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    • pp.1169-1174
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    • 2001
  • A new approach for determining global threshold value of binary image is proposed in this paper. In the proposed algorithm, bit-plane information which involve the shapes of original image is used for dividing image into two parts; object and background. Optimal threshold value are selected based on difference values of average between two regions, which is considered in global binary thresholding. Proposed method is no need to set a initial value, and consequently, it is relatively simple as well as robust. Experimental results showed a good performance in preserving edge not only continuous tone images but also document image.

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