• Title/Summary/Keyword: process stability

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Organizational Culture and Technological Innovation of SMEs in Daegu: The Moderating Effect of Job Stability and Environmental Uncertainty (대구지역 중소기업의 조직문화와 기술혁신: 고용안정성과 환경불확실성의 조절효과)

  • Im, Chae-Hyon;Shin, Jin-Kyo;Hwang, Su-Jung
    • Management & Information Systems Review
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    • v.31 no.1
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    • pp.183-203
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    • 2012
  • This paper investigates how small-medium firms deploy organizational culture, job stability and environmental uncertainty for technological innovation(product and process innovation). This paper suggests that organizational culture has significant effects on technological innovation, that job stability and environmental uncertainty moderate relationship between organizational culture and technological innovation. To test the hypotheses, data were collected from small-medium firms. The survey data of 258 firms were collected and integrated as the empirical base for testing the hypotheses. Major results are as follows: Firstly, when organizational culture as well as control variables are considered, organizational culture had significant and positive effects on product innovation. This result implies that organizational culture is an important means by which small-medium firms can promote innovation. Secondly, the interaction between organizational culture and job stability had a positive and significant effects on product innovation. Thirdly, the interaction between organizational culture and environmental uncertainty had a positive and significant effects on product innovation and process innovation. This paper suggests implications and several future researches need to overcome the limitations of this paper.

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Comparison of nitrogen removal efficiency on process stability for granular and immobilized anammox bacteria (공정 안정성에 대한 입상 및 고정화 혐기성 암모늄 산화균의 질소제거효율 비교)

  • Choi, Daehee;Bae, Hyokwan;Jung, Jinyoung;Kim, Sang-Hyoun
    • Journal of Korean Society of Water and Wastewater
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    • v.28 no.2
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    • pp.195-206
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    • 2014
  • Immobilization of anaerobic ammonium oxidizing bacteria has been studied to enhance the biomass retention of the slowly growing bacteria and the process stability. The purpose of this study was to compare the nitrogen removal efficiency of granular and immobilized anammox bacteria with poly vinyl alcohol and alginate. The specific anammox activity of the granular, homoginized and immobilized anammox bacteria were $0.016{\pm}0.0002gN/gVSS/d$, $0.011{\pm}0.001gN/gVSS/d$ and $0.007{\pm}0.0005gN/gVSS/d$, respectively. Although the activity decreased to 43.7 % of the original one due to low pH and $O_2$ exposure during the homogination and the immobilization, it was rapidly recovered within 7 days in the following continuous culture. When synthetic T-N concentrations of 100, 200, 400, 800 mg/L were fed, the immobilized anammox bacteria showed higher nitrogen removal efficiencies at all operational conditions than those of granular anammox bacteria. When the sludge retention time was shorten below 30.7 days and the reject water was fed, the nitrite removal efficiency of the granular anammox bacteria dropped to 8 % of the initial value, while that of the immobilized anammox bacteria was maintained over 95 % of the initial one. The immobilization with poly vinyl alcohol and alginate would be a feasible method to improve the performance and stability of the anammox process.

Sonoelectrodeposition of RuO2 electrodes for high chlorine evolution efficiencies (초음파 전기증착법을 활용한 고효율 염소 발생용 루테늄 옥사이드 전극)

  • Luu, Tran Le;Kim, Choonsoo;Yoon, Jeyong
    • Journal of Korean Society of Water and Wastewater
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    • v.31 no.5
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    • pp.397-407
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    • 2017
  • A dimensionally stable anode based on the $RuO_2$ electrocatalyst is an important electrode for generating chlorine. The $RuO_2$ is well-known as an electrode material with high electrocatalytic performance and stability. In this study, sonoelectrodeposition is proposed to synthesize the $RuO_2$ electrodes. The electrode obtained by this novel process shows better electrocatalytic properties and stability for generating chlorine compared to the conventional one. The high roughness and outer surface area of the $RuO_2$ electrode from a new fabrication process leads to increase in the chlorine generation rate. This enhanced performance is attributed to the accelerated mass transport rate of the chloride ions from electrolyte to electrode surface. In addition, the electrode with sonodeposition method showed higher stability than the conventional one, which might be explained by the mass coverage enhancement. The effect of sonodeposition time was also investigated, and the electrode with longer deposition time showed higher electrocatalytic performance and stability.

A Study on the Interactive Grain Stability Calculation (대화형 Grain Stability Calculation에 관한 연구)

  • Lee, S.S.;Lee, K.O.;Kang, W.S.;Yoon, M.T.;Sung, D.K.;Lee, J.C.
    • Journal of the Society of Naval Architects of Korea
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    • v.34 no.1
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    • pp.102-110
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    • 1997
  • In a shipyard, computer calculation is not frequently used for the grain stability calculation because of large difference between calculation values and real values. Therefore, the necessary calculation process for grain stability is done manually. GUI(Graphical User Interface) is adopted for the convenience of users and interactive data I/O. The hold shape (girder, hold, etc.)needed for calculation are visualized using GLBAX which is a 3 dimensional graphic library. The interface with the ship basic calculation package is also implemented. The aim of this paper is to develop a reliable interactive grain stability calculation program which reduces computational time, and is to computerize the grain stability calculation procedure.

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The Incapacition Method of Power System Assessing Transient Stability Index and Voltage Drop/Rise Duration Index (계통 안정도 모의를 통한 전력계통의 무력화 방안)

  • Lim, Jae-Sung;Kang, Hyun-Koo;Kim, Taek-Won;Moon, Seung-Il;Lim, Wan-Khun
    • Journal of the Korea Institute of Military Science and Technology
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    • v.12 no.4
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    • pp.532-539
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    • 2009
  • When assailing some area, it is important to consider targeting power system. This paper describes effective method that power networks are incapacitated based on assessing TSI and VDI. For this, we compose realistic scenario and analyze the simulation results in a view of stability. The simulation results show the destruction effects when occur the contingency in the specified area. To perform this process, the simulation tool PSS/E and DSAT are used.

Designing Fault-Tolerant Gaits for Quadruped Robots Using Energy Stability Margins (에너지 안정여유도를 이용한 사족 보행 로봇의 내고장성 걸음새)

  • Yang, Jung-Min
    • The Transactions of the Korean Institute of Electrical Engineers D
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    • v.55 no.7
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    • pp.319-326
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    • 2006
  • This paper proposes a novel fault-tolerant gait for Quadruped robots using energy stability margins. The previously developed fault-tolerant gaits for quadruped robots have a drawback of having marginal stability margin, which may lead to tumbling. In the process of tumbling, the potential energy of the center of gravity goes through a maximum. The larger the difference between the potential energy of the center of gravity of the initial position and that of this maximum, the less the robot tumbles. Hence this difference of potential energy, dubbed as Energy Stability Margin (ESM), can be regarded as the stability margin. In this paper, a novel fault-tolerant gait is presented which gives positive ESM to a quadruped robot suffering from a locked joint failure. Positive ESM is obtained by adjusting foot positions between leg swing sequences. The advantage of the proposed fault-tolerant gait is demonstrated in a case study where a quadruped robot with a failed leg walks on a even slope.

A Unified Framework for Small Signal Stability Analysis of Power Systems and Its Application to Available Transfer Capability (계통의 종합적 미소신호 안정도 해석 알고리듬과 ATC 산정에의 응용에 관한 연구)

  • Kim, Sang-Ahm;Song, Hwa-Chang;Lee, Byong-Jun;Kwon, Sae-Hyuk
    • The Transactions of the Korean Institute of Electrical Engineers A
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    • v.48 no.10
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    • pp.1222-1230
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    • 1999
  • This paper presents the framework for analysis of small-signal stability. In this framework the equilibrium points of system DAE model are traced using continuation method and instability points are determined on the solution path. Especially Implicit shift QR-modified Arnoldi method is utilized to calculated the rightmost eigenvalues. Small-signal stability is becoming one of the major factors that affect the ATC in the environment of deregulation. Stability limited ATC is easily evaluated in this stability analysis process.

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A Note to the Stability of Fuzzy Closed-Loop Control Systems

  • Hong, Dug-Hun
    • Journal of the Korean Data and Information Science Society
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    • v.12 no.1
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    • pp.89-97
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    • 2001
  • Chen and Chen(FSS, 1993, 159-168) presented a reasonable analytical model of fuzzy closed-loop systems and proposed a method to analyze the stability of fuzzy control by the relational matrix of fuzzy system. Chen, Lu and Chen(IEEE Trans. Syst. Man Cybern., 1995, 881-888) formulated the sufficient and necessary conditions on stability of fuzzy closed-loop control systems. Gang and Chen(FSS, 1996, 27-34) deduced a linguistic relation model of a fuzzy closed loop control system from the linguistic models of the fuzzy controller and the controlled process and discussed the linguistic stability of fuzzy closed loop system by a linguistic relation matrix. In this paper, we study more on their models. Indeed, we prove the existence and uniqueness of equilibrium state $X_e$ in which fuzzy system is stable and give closed form of $X_e$. The same examples in Chen and Chen and Gang and Chen are treated to analyze the stability of fuzzy control systems.

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A Study on the Deflection of Roller Axis of an Improved Mecanum Wheel Using the Castigliano Theorem (카스틸리아노 정리를 이용한 개선된 메카넘 휠의 롤러 축의 처짐에 대한 연구)

  • Hwang, Hui-Geon;Chung, Won-Jee;Kim, Dae-Young
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.19 no.6
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    • pp.61-66
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    • 2020
  • For simple and repetitive transport tasks in limited spaces such as in factories, it is more efficient to use mobile robots instead of human workers. For this reason, the reliance on mobile robots is increasing due to the increased implementation of smart factories. Currently, the structural design of the Mecanum wheel is required to ensure the stability of the moving robot since it is used for the transport of not only small products but also large products. In this paper, to improve the stability and durability of the Mecanum wheel, ways to improve the structure of the Mecanum wheel are presented. Then, using the Castigliano theorem, the structural stability is reviewed through the deflection on existing and improved structures.

Structural Analysis on Door Hinge of Car (자동차 도어 힌지의 구조해석)

  • Cho, Jae-Ung;Han, Moon-Sik
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.9 no.2
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    • pp.33-39
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    • 2010
  • The thickness of original hinge model is changed for structural stability in this study. The front end with the largest deformation of 9.8813 mm or the rear middle part with the largest equivalent stress of 6082.6 MPa is respectively shown at door hinge. The lower part of joint pin head with the largest deformation of 0.17499 mm and the largest equivalent stress of 1540.2 MPa are shown. The advanced model with more thickness and stability is shown to have smaller displacement in half and smaller equivalent stress by 3 times by comparing with the original model.