• Title/Summary/Keyword: External and internal stability

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Delay-dependent Stabilization of Singular Systems with Multiple Internal and External Incommensurate Constant Point Delays

  • Xie, Yong-Fang;Gui, Wei-Hua;Jiang, Zhao-Hui
    • International Journal of Control, Automation, and Systems
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    • v.6 no.4
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    • pp.515-525
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    • 2008
  • In this paper, the problem of delay-dependent stabilization for singular systems with multiple internal and external incommensurate constant point delays is investigated. The condition when a singular system subject to point delays is regular independent of time delays is given and it can be easily test with numerical or algebraic methods. Based on Lyapunov-Krasovskii functional approach and the descriptor integral-inequality lemma, a sufficient condition for delay-dependent stability is obtained. The main idea is to design multiple memoryless state feedback control laws such that the resulting closed-loop system is regular independent of time delays, impulse free, and asymptotically stable via solving a strict linear matrix inequality (LMI) problem. An explicit expression for the desired memoryless state feedback control laws is also given. Finally, a numerical example illustrates the effectiveness and the availability for the proposed method.

Study on Cyber Fashion for the Proposal of the Future Fashion (미래 패션 제안을 위한 사이버 패션 연구)

  • Lee, Su-Aa;Park, Hyun
    • Fashion & Textile Research Journal
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    • v.1 no.3
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    • pp.239-245
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    • 1999
  • The purpose of this study is to suggest the direction of the future fashion by grasping the cyber fashion, which is discussed outstandingly in the recent fashion world, into internal expression and external features. The result of this study is as follows: Cyber fashion means the application of the electronic image, dynamic phenonmenon of machine, and the effects of light to fashion, and it has some external features of geometrical pattern, dynamic structure, and high-tech material and color: Aside from this noticeable characteristics, cyber fashion has some internal features of the direction toward future, the anti-culture, and the surreal. In this cyber fashion, first, computer will be introduced and used as the means to realize a dream of human being. Second, it will be designed with the ideal feature of future society. Third, it will be possible to develope material and design to solve ecological issue of human beings. Fourth, the fashion to give the peace and stability to human being will be popular.

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Reliability Analysis of a Quay Wall Constructed on the Deep-Cement-Mixed Ground (Part II: Internal Stability of the Improved Soil System) (심층혼합처리지반에 설치된 안벽의 신뢰성해석 (Part II: 개량지반의 내부안정))

  • Huh, Jung-won;Park, Ock-Joo;Kim, Young-Sang;Hur, Dong-Soo
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.22 no.2
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    • pp.88-94
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    • 2010
  • A reliability analysis method is proposed in this paper to quantitatively evaluate the risk for internal stability of a quay wall constructed on the deep cement mixed ground, differentiating from the companion paper that mainly describes the external stability. Failure modes for toe pressure, shear strength of improved ground and extrusion of unimproved soft soil are investigated and compared in the risk estimation of internal stability using MVFOSM, FORM, and MCS. From the reliability analysis results for internal stability of a quay wall, the variance and distribution type of the compressive strength of Deep Mixed Soil-Cement appear to be very affective to the failure probability. On the other hand, other random variables seem to be relatively very insensitive to the probability of failure. It is therefore very important to rationally and accurately determine the probabilistic properties of the in-site compressive strength of Deep Mixed Soil-Cement.

Analysis of Multi-Chained and Multiple Contact Characteristics of Foot Mechanisms in Aspect of Impulse Absorption (다수 체인과 다중 접촉 성격을 지닌 발 메커니즘에 대한 충격량 흡수 기반 해석)

  • Seo, Jong-Tae;Oh, Se Min;Yi, Byung-Ju
    • The Journal of Korea Robotics Society
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    • v.12 no.2
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    • pp.161-172
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    • 2017
  • Foot mechanisms play the role of interface between the main body of robotic systems and the ground. Biomimetic design of the foot mechanism is proposed in the paper. Specifically, multi-chained and multiple contact characteristics of general foot mechanisms are analyzed and their advantages are highlighted in terms of impulse. Using Newton-Euler based closed-form external and internal impulse models, characteristics of multiple contact cases are investigated through landing simulation of an articulated leg model with three kinds of foot. It is shown that in comparison to single chain and less articulated linkage system, multi-chain and articulated linkage system has superior characteristic in terms of impulse absorption as well as stability after collision. The effectiveness of the simulation result is verified through comparison to the simulation result of a commercialized software.

Evaluation of Stability of Double Threaded Implant-Emphasis on Initial Stability Using Osstell MentorTM; Part I (이중나사산 임플란트의 안정성에 대한 평가 - 오스텔 멘토를 이용한 초기 안정성 ; PART I)

  • Kim, Si-Yeob;Kim, Byung-Kook;Heo, Jin-Ho;Lee, Ju-Youn;Jeong, Chang-Mo;Kim, Yong-Deok
    • Journal of Dental Rehabilitation and Applied Science
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    • v.23 no.4
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    • pp.327-336
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    • 2007
  • Purpose This study was planned to compare and evaluate the stability of implant using $Osstell^{TM}$ and Osstell $Mentor^{TM}$. Material and methods Artificial bone and RBM(resorbable blasting media) surface blasted implants(Osstem US II, SS II implants - diameter: 4mm, length: 13mm) were used. To measure the stability of installed implants, $Osstell^{TM}$ and Osstell $Mentor^{TM}$ were used. In the first experiment, five implants were installed in D1(external type implants) and D3(internal type implants). In the second experiment, 4 internal type implants were divided in two groups and installed in D1 artificial bone with different depth. In the third experiment, two external implants were installed in D1 and D3 artificial bone each and two internal implants were installed in D1 and D3 artificial bone. In all groups, their stability were measured by $Osstell^{TM}$ and Osstell $Mentor^{TM}$. Results In all groups, $Osstell^{TM}$ and Osstell $Mentor^{TM}$ both showed reliable measurement values. The value difference between $Osstell^{TM}$ and Osstell $Mentor^{TM}$ was observed but the difference was small and clinically acceptable. Conclusion These results suggest that the use of Osstell $Mentor^{TM}$ has clinical relevance in the assessment of implant stability.

The Study on the Simple Measurement by Using the Strain Gauge at Dam Dynamic Behavior Analysis (댐 거동 분석에서의 Strain Gauge를 이용한 단일 계측에 관한 연구)

  • Lee, Seungho
    • Journal of the Korean GEO-environmental Society
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    • v.8 no.1
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    • pp.5-11
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    • 2007
  • Internal stress variation in the face slab concrete induced by reservoir water pressure may affect on the stability of the dam so that the reclamation type of strain gauge is applied for measuring internal stress variation. In this study, internal as well as external stress variation of dam was measured by using strain gauge that was reclaimed to the ${\circ}{\circ}$ dam. In the result, it was confirmed that other measurements by relevant gauges need to be supplemented as the use of strain gauge only is insufficient to evaluate the stability analysis and global behavior of the dam.

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The Relationship Between Internal Auditors' Personality Traits, Internal Audit Effectiveness, and Financial Reporting Quality: Empirical Evidence from Jordan

  • ALBAWWAT, Ibrahim Emair;AL-HAJAIA, Mohammad Eid;AL FRIJAT, Yaser Saleh
    • The Journal of Asian Finance, Economics and Business
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    • v.8 no.4
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    • pp.797-808
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    • 2021
  • This study examines the interaction between internal auditors' personality traits and the internal audit function effectiveness. It also investigates the effect of such interacted variables on financial reporting quality. This study employed a questionnaire survey to collect data from 193 internal auditors of Jordanian companies listed on the Amman Stock Exchange. The study model is validated and tested using the partial least squares structural equation modelling. The results reveal that all the examined personality traits of internal auditors significantly impact internal audit function effectiveness except for the extraversion trait. The results also show that personality traits have indirect effects on financial reporting quality via internal audit function effectiveness. These results suggest that internal auditors with high scores on openness to experience, emotional stability, and conscientiousness traits can be among the most significant contributors to the internal audit function effectiveness. The results also suggest that internal auditors' personality traits can be regarded as an internal audit function intangible resource that enhances effectiveness. The study's findings might be of interest to many different parties interested in enhancing internal audit function effectiveness and boosting the financial reporting quality, such as external and internal auditors, auditees, human resource departments, and Chief Internal Audit Executives.

A Percentage Current Differential Relay for Bus Protection Using a Compensation Algorithm Unaffected by a Remanent Flux (잔류자속에 무관한 보상 알고리즘을 적용한 모선보호용 전류차동 계전방식)

  • Kang, Yong-Cheol;Yun, Jae-Sung;Lim, Ui-Jai
    • Proceedings of the KIEE Conference
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    • 2003.07a
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    • pp.308-310
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    • 2003
  • This paper proposes a percentage current differential relaying algorithm for bus protection with a compensation algorithm of a CT. The compensating algorithm estimates the core flux at the start of the first saturation based on the value of the third-difference of the secondary current. It calculates the core flux and compensates distorted currents in accordance with the magnetization curve. The test results indicate that the algorithm can discriminate internal faults from external faults when the CT saturates. It can improve not only stability of the relay in the case of an external fault but sensitivity of the relay in the case of an internal fault.

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A Percentage Current Differential Relaying Algorithm for Bus Protection Using an Advanced Compensating Algorithm of the CTs (개선된 변류기 보상알고리즘을 적용한 모선보호용 비율전류차동 계전방식)

  • 강용철;윤재성;강상희
    • The Transactions of the Korean Institute of Electrical Engineers A
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    • v.52 no.3
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    • pp.158-164
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    • 2003
  • This paper proposes a percentage current differential relaying algorithm for bus protection using an advanced compensating algorithm of the secondary current of current transformers (CTs). The compensating algorithm estimates the core flux at the start of the first saturation based on the value of the second-difference of the secondary current. Then, it calculates the core flux and compensates distorted currents using the magnetization curve. The algorithm Is unaffected by a remanent flux. The simulation results indicate that the proposed algorithm can discriminate internal faults from external faults when the CT saturates. This paper concludes by implementing the algorithm into a TMS320C6701 digital signal processor. The results of hardware implementation are also satisfactory. The proposed algorithm can improve not only stability of the relay in the case of an external fault but sensitivity of the relay in the case of an internal fault.

Experimental Study on the Internal Flow Characteristics in a Swirl Coaxial Injector for Gas Generator (가스발생기용 스월 동축형 인젝터에서 내부 유동의 특성에 대한 실험적 연구)

  • Kim, Sung-Hyuk;Yoon, Jung-Soo;Yoon, Young-Bin
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2010.05a
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    • pp.29-33
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    • 2010
  • This study aim to investigate the internal flow characteristics by recess length of swirl coaxial injector for gas generator has propellant of Kerosene-LOx. Recess length is a very important element, have influence in spray stability and LOx post damage. The influence of recess length was analyzed by visualizing internal flow and measuring liquid film thickness and manifold pressures. Also, each spray characteristic by recess length was investigated in internal or external injector.

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