• Transactions of the Korean Society of Mechanical Engineers A
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• v.26 no.10
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• pp.2067-2072
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• 2002

The closed-loop state and input observer is a pole-placement type observer and estimates unknown state and input variables simultaneously. Pole-placement type observers may have poor performances with respect to modeling error and sensing bias error. The effects of these ill-conditioning factors must be minimized for the robust performance in designing observers. In this paper, the steady-state performance of the closed-loop state and input observer is investigated quantitatively and is represented as the estimation error bounds. The performance indices are selected from these error bounds and are related to the robustness with respect to modeling errors and sensing bias. By considering both transient and steady-state performance, the main performance index is determined as the condition number of the eigenvector matrix based on $L_2$-norm.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.26 no.10
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• pp.2060-2066
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• 2002

The closed-loop state and input observer is a pole-placement type observer and estimates unknown state and input variables simultaneously. Pole-placement type observers may have poor transient performance with respect to ill-conditioning factors such as unknown initial estimates, round-off error, etc. For the robust transient performance, the effects of these ill-conditioning factors must be minimized in designing observers. In this paper, the transient performance of the closed-loop state and input observer is investigated quantitatively by considering the error bounds due to ill-conditioning factors. The performance indices are selected from these error bounds and are related to the observer robustness with respect to the ill -conditioning factors. The closed-loop state and input observer with small performance indices is considered as a well-conditioned observer from the transient perspective.

• The Journal of Asian Finance, Economics and Business
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• v.7 no.4
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• pp.97-105
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• 2020

This paper explores the impact of capital structure on firm performance in the context of Vietnam. The paper investigates the different effect of capital structure on firm performance in state-owned and non-state enterprises listed on the Vietnam stock market. The panel data of research sample includes 488 non-financial listed companies on the Vietnam stock market for a period of six years, from 2013 to 2018. The Generalized Least Square (GLS) is employed to address econometric issues and to improve the accuracy of the regression coefficients. In this research, firm performance is measured by return on equity (ROE), return on assets (ROA), and earnings per share (EPS). The ratios of short-term liabilities, long-term liabilities, and total liabilities to total assets are proxy for capital structure. Firm sizes, growth rate, liquidity, and ratio of fixed assets to total assets are control variables in the study. The empirical results show that capital structure has a statistically significant negative effect on the firm performance. The result also shows this effect is stronger in state-owned enterprises than non-state enterprises in Vietnam. These evidences provide a new insight to managers of both state-owned and non-state enterprises on how to improve the firm's performance with capital structure.

• The Korean Journal of Food & Health Convergence
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• v.7 no.3
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• pp.13-23
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• 2021

The purpose of this study was to explain the influence of motivation, leadership, and discipline on the performance of the midwife at Sharia Hospital X in Central Java Indonesia before the Covid-19 pandemic. This research is a combination between quantitative research and qualitative research (mix method). The population in this study were all midwives sharia hospital x in central java Indonesia, totaling 75 people. The primary data in this study came from questionnaires, interviews, observation, and documentation, then from the results of the analysis and data processing the researcher interpreted it more deeply using qualitative methods. The results of this study conclude that motivation, leadership, and discipline are proven to have a positive and significant effect on the performance of midwives, thus it can be concluded that an increase in motivation, leadership, and discipline in work will be able to improve the performance of the midwifes Sharia Hospital X. These results give an understanding that every time there is an increase in motivation, leadership, and work discipline, it will increase the performance of the midwifes. Motivation is the biggest variable affecting the performance, leadership is the second and work discipline is the smallest variable that affects the performance of midwives.

• Journal of the Korean Ceramic Society
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• v.49 no.4
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• pp.295-300
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• 2012

SiC-based ceramic matrix composites show many advantages over their monolithic ceramic counterparts, which makes them potential candidates for applications in various fields. Depending strongly on the chemical composition and microstructure of the fiber reinforcement, matrix as well as the fiber/matrix interphase in the material, the properties of ceramic matrix composites(CMCs) are highly tailorable. In this paper, the latest progresses in the interphase design, matrix modification and fiber reinforcement decoration of CMCs are reviewed, their effects on the properties of the CMCs are introduced.

• Proceedings of the Korea Society for Simulation Conference
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• 2005.11a
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• pp.13-18
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• 2005

Routers determine routing path considering network topology and link state information for providing QoS (quality of service) guarantee. Therefore, it is important that routers know link state information to calculate routing path. However, if routers generate link state update messages inordinately, their router performance are reduced due to the process of link state update messages. On the other side, in case that link state information is not updated appropriately, route setup requests can be rejected even though there exist routes. In this paper, we propose an algorithm to improve router performance and evaluate the proposed algorithm performance compare with conventional algorithm by simulations.

• Journal of Power Electronics
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• v.17 no.4
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• pp.1027-1036
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• 2017

The brushless doubly-fed induction generator (BDFIG) is a new type of dual stator winding induction generator. In such a generator, both the power winding (PW) and the control winding (CW) are housed in the stator. This paper presents the performance characteristics of a stand-alone BDFIG operation system. A new T-type steady-state model of a BDFIG is proposed. This model is more suitable for the performance analysis of stand-alone BDFIGs than the conventional Π-type steady-state model and the simplified inner core steady-state model. The characteristics of the power flow and CW current are analyzed by detailed mathematical derivations on the basis of the proposed T-type steady-state model. The analysis results are verified by experiments, which are carried out on a prototype BDFIG. The results of the performance analysis contribute to simplifying the control circuit, improving the control performance, and selecting an appropriate BDFIG for actual industrial applications.

• Journal of Communications and Networks
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• v.13 no.6
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• pp.591-601
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• 2011

Today's Internet which provides communication channels with best-effort end-to-end performance is rapidly evolving into an autonomic global computing platform. Achieving autonomicity in the Future Internet will require a performance architecture that (a) allows users to request and own 'slices' of geographically-distributed host and network resources, (b) measures and monitors end-to-end host and network status, (c) enables analysis of the measurements within expert systems, and (d) provides performance intelligence in a timely manner for application adaptations to improve performance and scalability. We describe the requirements and design of one such "Future Internet performance architecture" (FIPA), and present our reference implementation of FIPA called 'OnTimeMeasure.' OnTimeMeasure comprises of several measurement-related services that can interact with each other and with existing measurement frameworks to enable performance intelligence. We also explain our OnTimeMeasure deployment in the global environment for network innovations (GENI) infrastructure collaborative research initiative to build a sliceable Future Internet. Further, we present an applicationad-aptation case study in GENI that uses OnTimeMeasure-enabled performance intelligence in the context of dynamic resource allocation within thin-client based virtual desktop clouds. We show how a virtual desktop cloud provider in the Future Internet can use the performance intelligence to increase cloud scalability, while simultaneously delivering satisfactory user quality-of-experience.

• The Journal of Asian Finance, Economics and Business
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• v.7 no.10
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• pp.663-673
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• 2020

To enhance the performance of privatized firms and state-owned enterprises, Vietnamese government set up a specialized monitoring body named State Capital Investment Corporation (SCIC) in 2006 to supervise their performance. This motivated us to conduct this study to investigate the effective control of SCIC on privatized firms' performance. We collected the annual reports of 500 non-financial privatized firms listed on HSX and HNX during the period from 2007 to 2017 from Thomson Reuters. Observations with missing values were removed and trimming outliers were implemented resulting in a dataset comprising of 4146 firm-year observations. We applied a quadratic regression model of state ownership on firms' performance, and applied the method of Baron and Kenny (1986) to test the moderating effect of SCIC control. To fix "selection bias" that may occur and result in endogeneity of moderator (M), we utilized the PSM technique to analyze the marginal effect of the moderator (SCIC) on privatized firms' performance. Our findings indicate a positive moderating role of SCIC on the relationship between the state ownership and firms' performance. This implies that there is a positive effect of liberating the management of the private firms from government control, which also means that lesser the intervention of government in the day to day operational activities of a private firm, better the performance of a privatized firm is.

• Journal of Institute of Control, Robotics and Systems
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• v.6 no.8
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• pp.672-681
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• 2000

Based on the dynamic anti-windup strategy a novel control methodology for state constrained control systems is presented. First a linear controller is designed for an open-loop stable plant to show a desirable nominal performance by ignoring state constraints. And then an additional dynamic compensator is introduced to preserve the nominal performance as closely as possible int he face of state constraints. This paper focuses on the second step under the assumption that a linear controller has already been designed appropriately by using an effective controller design method. By minimizing a reasonable performance index the dynamic compensator is derived explicitly which is expressed int he plant and controller parameters. the proposed method not only guarantees the total stability of the overall resulting systems but also provides desirable output performance because it solves the state-positioning problem completely.