• Title/Summary/Keyword: in-use stability

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Improved Thermal Stability of Ag Nanowire Heaters with ZnO Layer (ZnO를 이용한 은 나노와이어 히터의 열 안정성 향상)

  • Choi, Wonjung;Jo, Sungjin
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.30 no.8
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    • pp.530-534
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    • 2017
  • Transparent film heaters employing silver nanowires (Ag NWs) have attracted increasing attention because of their widespread applications. However, the low thermal resistance of Ag NWs limits the maximum operating temperature of the Ag NW film heater. In this study, Ag NW film heaters with high mechanical and thermal stability were successfully developed. The thermal power-out characteristics of the Ag NW heaters were investigated as a function of the Ag NW density. The results revealed that the prepared flexible Ag NW heater possessed high thermal stability over $190^{\circ}C$ owing to ZnO encapsulation. This indicates that the Ag NW film with excellent thermal stability have remarkably high potential for use as electrodes in film heaters operating at high temperatures.

Comparison of Biomechanical Stability of Custom-made Hip Implants using Finite Element Analysis (스템 길이에 따른 환자맞춤 인공고관절의 역학적 안정성 비교)

  • Jun, Yongtae
    • Korean Journal of Computational Design and Engineering
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    • v.21 no.4
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    • pp.426-432
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    • 2016
  • Designing a morphologically well-fitted hip implant to a patient anatomy is desirable to improve surgical outcomes since a commercial ready-made hip implant may not well conform to the patient joint. In this study, biomechanical stability of patient-specific hip implants with two different stem lengths was compared and discussed using a 3D finite element analysis (FEA). The FEA results in this study showed that an increase in stem length brings about more the peaked von-Mises stress (PVMS) in the prosthesis and less in the femur. However the decrease in von-Mises stress in the femur causes stress shielding phenomenon that usually leads to considerable bone resorption. Although, in biomechanical stability point of view, this work recommends the use of smaller stems, the length of stem must be determined by considering both the von-Mises stress and the stress-shielding phenomenon.

Transient Stability Enhancement by DSSC with Fuzzy Supplementary Controller

  • Khalilian, Mansour;Mokhtari, Maghsoud;Nazarpour, Daryoosh;Tousi, Behrouz
    • Journal of Electrical Engineering and Technology
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    • v.5 no.3
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    • pp.415-422
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    • 2010
  • The distributed flexible alternative current transmission system (D-FACTS) is a recently developed FACTS technology. Distributed Static Series Compensator (DSSC) is one example of DFACTS devices. DSSC functions in the same way as a Static Synchronous Series Compensator (SSSC), but is smaller in size, lower in price, and possesses more capabilities. Likewise, DSSC lies in transmission lines in a distributed manner. In this work, we designed a fuzzy logic controller to use the DSSC for enhancing transient stability in a two-machine, two-area power system. The parameters of the fuzzy logic controller are varied widely by a suitable choice of membership function and parameters in the rule base. Simulation results demonstrate the effectiveness of the fuzzy controller for transient stability enhancement by DSSC.

Design and Implementation of an MPEG-2 AAC Format-based Audio Streaming System (MPEG-2 AAC 포맷 기반의 오디오 스트리밍 시스템 설계 및 구현)

  • 이승재;이승룡
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.27 no.12C
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    • pp.1251-1264
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    • 2002
  • Currently, audio streaming services such as on-demand service and live service support only a limited number of clients. They also suffer from a lack of stability and degradation of service quality due to their inefficient use of network resources. Futhermore, since the streaming services usually do not consider dynamic services, they are very inconvenience to use. In order to resolve these drawbacks, we propose a novel audio streaming system based on MPEG-2 AAC file format which are facilitated with the network bandwidths efficiently. The proposed system supports QoS for audio streaming as well as guarantees a stability while streaming service is undergoing. Moreover, the system provides a dynamic interface which enables us to use the streaming service more easily and to manage streaming servers with convenient manner. On the contrary, most of the current available static interface streaming services are mainly depending only on a single fixed web page between client and server, which in consequence lead us to use unflexible static service environment. Our implementation results show the proposed system improves the performance compared to those of the currently existing systems that use MP3 file format. It also provides some benefits such as a stability of service and a easy to management of streaming servers.

A Development of 4-legged Walking Machine and the Enhancement of Static Stability Margin Using Balancing Weight (사각 보행 로보트의 제작 및 균형추를 이용한 안정성 향상에 관한 연구)

  • 강신천;오준호;정경민
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1991.11a
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    • pp.146-154
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    • 1991
  • As the application of robotic systems expand its scope, more research efforts are given in providing mobility to the robotic systems so that they can travel across various paths including those with formidable obstacles such as stairways or rough terrains. Legged locomotion is mainly concerned because the walking motion, like that of animal behavior, has many advantages over wheel type or track type locomotion especially in rough terrain. Walking robot, in general, having a discrete number of legs, have inherently low static stability. Static stability can be increased to a certain degree, by improving walking method, but it has many limitations such as reduced travel speed. A very promising possibility lies in the use of balancing weight, nevertheless its actual implementation is very rare. In this study, a 4-legged walking machine is developed and the static stability margin is increased with the balancing weight. In the future, this robot will be used to take an experiment on the walking in mush terrain.

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The Impact of Financial Inclusion on Financial Stability in Asian Countries

  • PHAM, Manh Hung;DOAN, Thi Phuong Linh
    • The Journal of Asian Finance, Economics and Business
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    • v.7 no.6
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    • pp.47-59
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    • 2020
  • This paper intends to explore the relationship between financial inclusion and financial stability under the scope of Asian economies. The linkage will be thoroughly investigated with country-level and bank-level data of 42 countries in three separate years: 2011, 2014, and 2017. In this study, an inclusive financial system is assessed by two dimensions: usage of financial services and access to the financial system. Usage of financial services ranges from account to credit, savings and payment services. Access to financial system measures the financial outreach where individuals can use financial services. Meanwhile, financial stability, which proxied by Bank Z-score is regarded as the dependent variable. We apply fixed effects regression and random effects regression to capture the impacts of financial inclusion upon financial stability. To enhance the robustness of the model, the Feasible Generalized Least Squares (FGLS) regression is therefore adopted as the solution for the random effects regression. The empirical findings exhibit an overall weak positive influence of financial inclusion on financial stability. The research results also provide both financial institutions and governments with insightful information, which helps them to have an appropriate financial development strategy, improve the regulatory framework and consequently enhance financial stability for the whole system.

Case of slope stability in weathered metamorphic rock (풍화된 변성암 사면의 안정대책 사례)

  • Kim, Jae-Hong;Park, Chal-Sook;Jeon, Je-Sung;Hong, Won-Pho
    • Proceedings of the Korean Geotechical Society Conference
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    • 2008.03a
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    • pp.1400-1405
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    • 2008
  • Execute surface of the earth geological survey for stability analysis of stealing cutting sides and investigated wide area nature of soil structure. Inflected DIPS that measure discontinuity's direction that develop to slope and is slope stability a wide use program for Stereographic Projection Method analysis that utilize geometrical correlation of stealing four sides and discontinuity surface. It is principle that angle of internal friction that is basis element of stability estimation applies direct shear test result on joint side, Examination is impossible by case execution, suppose by 30 angles that apply more conservatively in base rock slope sides usually and achieved analysis. When analyze, consider discontinuity's various adult that develop in research slope, after conduct first each discontinuity different assay falling into fault, joint, executed stability estimation which synthesize whole discontinuity data. When ailment element is recognized as analysis result, wished to present stability countermeasure way of most suitable to take into account of execution, stability, economic performance.

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COMPARATIVE STUDY ON THE POSITIONAL STABILITY OF REMOVABLE DIES USING SEVERAL DOWEL PIN SYSTEMS (수종의 dowel pin systems을 이용한 가철성 다이의 위치 안정성에 관한 비교 연구)

  • Jeong, Jae-Hyang;Jeong, Chang-Mo;Jeon, Young-Chan
    • The Journal of Korean Academy of Prosthodontics
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    • v.36 no.5
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    • pp.738-747
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    • 1998
  • The purpose of this study was to compare the positional stability of removable dies using several dowel pin systems. The removable dies were made by using five dowel pin systems: single dowel pin(Group I), single dowel pin and prepared groove on the die base(Group II), two-single dowel pin(Group III), two separate parallel dowel pins with plastic sleeves(Group IV), double straight dowel pins with metal sleeve(Group V). Special aluminum mold was made for specimens, and the dies of specimens removed and replaced thirty times with universal testing machine. Horizontal and vertical shift of dies was measured by Olympus monocular scanning tunneling microscope(STM5). The results were as follows: 1. The vertical shift was larger than the horizontal shift in all the other groups except Group I. 2. Single dowel pin system(Group I) was the most unstable of five dowel pin systems. 3. Double dowel pin systems with steeve(group IV, V) were the most stable of five dowel pin systems. 4. This study indicates that excellent horizontal positional stability is attainable with use of additional groove on the die base or double dowel pin. and excellent vertical positional stability is attainable with use of sleeve.

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Implementation of Improved safety and reliability Embedded system using Backup and Restore of TMR Architecture (TMR 구조에서의 백업과 복원을 활용한 안정성 및 신뢰성 향상 임베디드 시스템 구현)

  • Park, Joo-Yul;Lee, Jun-Hwan;Kim, Hyo-Sang;Kim, Bong-Taek;Chung, Ki-Seok
    • Proceedings of the KSR Conference
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    • 2011.10a
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    • pp.188-194
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    • 2011
  • The purpose of this paper is to explain the implementation method in order to enhance stability and reliability of embedded system. In this research, Texas Instrument (TI)'s TMS570 MCU(Micro Controller Unit) is used to satisfy the standard of stability that is IEC 61508. IEC 61508 suggest SIL(Safety Integrity Level) from 1 to 4 and TMS570 is satisfied SIL3. Also, TMS570 can provide several stability functions can be used in realtime system. To use such functions, this paper suggest the solution about the defect that can be used in realtime system. In basic way TMR(Triple Modular Redundancy) suggested in addition to explain about the way to improve safety and reliability. Also this paper will suggest the method that reinforce the stability of calculation by using multiplex voter and memory.

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An Overview of Flutter Prediction in Tests Based on Stability Criteria in Discrete-Time Domain

  • Matsuzaki, Yuji
    • International Journal of Aeronautical and Space Sciences
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    • v.12 no.4
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    • pp.305-317
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    • 2011
  • This paper presents an overview on flutter boundary prediction in tests which is principally based on a system stability measure, named Jury's stability criterion, defined in the discrete-time domain, accompanied with the use of autoregressive moving-average (AR-MA) representation of a sampled sequence of wing responses excited by continuous air turbulences. Stability parameters applicable to two-, three- and multi-mode systems, that is, the flutter margin for discrete-time systems derived from Jury's criterion are also described. Actual applications of these measures to flutter tests performed in subsonic, transonic and supersonic wind tunnels, not only stationary flutter tests but also a nonstationary one in which the dynamic pressure increased in a fixed rate, are presented. An extension of the concept of nonstationary process approach to an analysis of flutter prediction of a morphing wing for which the instability takes place during the process of structural morphing will also be mentioned. Another extension of analytical approach to a multi-mode aeroelastic system is presented, too. Comparisons between the prediction based on the digital techniques mentioned above and the traditional damping method are given. A future possible application of the system stability approach to flight test will be finally discussed.