• Title/Summary/Keyword: External stability

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Marital Satisfaction and Marital Stability : A Comparison of Two Theoretical Models (결혼만족도와 결혼안정성 : 두 이론의 비교)

  • 윤경자
    • Journal of the Korean Home Economics Association
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    • v.35 no.4
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    • pp.31-46
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    • 1997
  • The controversy between Lewis and Spanier's theory and Thomas and kleber's theory on marital satisfaction and marital stability was tested empirically. The results show that while marital satisfaction was the best predictor for marital stability the impact of alternative attractions and external pressures to remaim married was more complicated than both theories predicted depending on the nature of alternative attractions. Thomas and Kleber's theory was supported in most of groups Contrary to Lewis and Spanier's theory alternative atteractions did not negatively affect marital stability of marriages of high qulity. Contrary to both theories external pressures to remain married was not an important predictor of marital stability . In some cases high external pressures to remain married even lowered marital stability. The validity of both theories are discussed.

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A study on an adaptive gait for a quadruped walking robot under external forces (외력 대처 기능을 갖는 사각 보행 로보트 적응 걸음새에 관한 연구)

  • ;;;;Zeungnam Bien
    • Journal of the Korean Institute of Telematics and Electronics B
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    • v.33B no.9
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    • pp.1-12
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    • 1996
  • In this paper, we propose an adaptive gait by which a quadruped walking robot can walk against external disturbances. This adaptive gait mechanism makes it possible for a quadruped walking robot to change its gait and accommodate external disturbances form various external environmental factors. Under the assumption that external disturbances can be converted to an external force acting on the body of a quadruped walking robot, we propose a new criterion for the stability margin of a waling robot by using an effective mass center based on the zero moment point under unknown external force. And for a solution of an adaptive gait against external disturbances, an method of altitude control and reflexive direction control is suggested. An algorithmic search method for an optimal stride of the quadruped mehtod, the gait stability margin of a quadruped walking robot is optimized in changing its direction at any instance for and after the reflexive direction control. To verify the efficiency of the proposed approach, some simulaton results are provided.

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How Vulnerable is Indonesia's Financial System Stability to External Shock?

  • Pranata, Nika;Nurzanah, Nurzanah
    • The Journal of Asian Finance, Economics and Business
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    • v.4 no.2
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    • pp.5-17
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    • 2017
  • The main objective of the study is to measure the vulnerability of Indonesia's financial system stability in response to external shocks, including from regional economies namely three biggest Indonesia major trading partners (China, the U.S and Japan) and other external factors (oil price and the federal funds rate). Using Autoregressive Distributed Lag (ARDL) model and Orthogonalized Impulse Response Function (OIRF) with quarterly data over the period Q4 2002 - Q1 2016, results confirm that, 1) oil price response has the largest effect to Indonesia financial stability system and the effect period is the longest compared to others, represented by NPL and IHSG; 2) among those three economies, only China's economic growth has significantly positive effect to Indonesia financial stability system. Based on the findings it is better for the authorities to: 1) Diversify international trade commodities by decreasing share of oil, gas, and mining export and boosting other potential sectors such as manufacture, and fisheries; 2) Ensure the survival of Indonesia large coal exporter companies without neglecting burden of national budget; and 3) Create buffer for demand shock from specific countries by diversifying and increasing share of trading from other countries particularly from ASEAN member states.

Analysis of Postural Stability in Response to External Perturbation Intensity in Dancers and Non-dancers

  • Park, Da Won;Koh, Kyung;Lee, Sung Ro;Park, Yang Sun;Shim, Jae Kun
    • Korean Journal of Applied Biomechanics
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    • v.26 no.4
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    • pp.427-432
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    • 2016
  • Objective: The goal of this study was to systematically investigate the postural stability of dancers by providing unexpected perturbations. Method: Six female dancers and college students participated in this study. Unpredictable wait-pull balance perturbations in the anterior direction were provided to the participants during standing. Three different perturbation intensities (low, moderate, and high intensity) were used by increasing perturbation forces. Spatial and temporal stability of postural control were measured by using margin of stability (MoS) and time to contact (TtC), respectively. Results: Both MoS and TtC at moderate intensity were significantly greater in the dancer group than in the control group, but no significant differences were found at low and high intensities between the groups. Conclusion: The present study showed spatial and temporal stability of dynamic postural control in dancers. We found that the dancers were more spatially and temporally stable than the ordinary participants in response to unexpected external perturbation when the perturbation intensity was moderate at two extreme intensity levels (low and high).

Stability evaluation of reinforced earth walls based on large-scale modular blocks (대형 축조블록을 이용한 보강토옹벽의 안정성 평가)

  • Han, Jung-Geun;Kim, Min-Woo;Hong, Kikwon;Yun, Jung-Mann
    • Journal of the Korean Geosynthetics Society
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    • v.13 no.4
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    • pp.143-151
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    • 2014
  • This paper describes external and internal stability of reinforced earth wall using large-scale modular block and geogrid reinforcement. The evaluation for external and internal stability was conducted to analyze effect of wall height, reinforced soil (or backfill soils) and reinforcement strength. The external stability showed that the analysis cases were satisfied with design criteria, when the required minimum length and vertical spacing of reinforcement were 0.7H and 1m, respectively. The internal stability conformed that some cases were satisfied with design criteria in $25^{\circ}$ of internal friction angle of reinforced soil. Expecially, it will be applicable as wall structure considering a structural stability and economic efficiency based on evaluation of internal stability.

Stability Properties of Semiconductor Lasers with Optical Feedback from an External Grating

  • Park, Jong-Dae;Cho, Chang-Ho;Kim, Chil-Min
    • Korean Journal of Optics and Photonics
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    • v.2 no.3
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    • pp.153-157
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    • 1991
  • We report an analysis on the stability properties of external cavity semiconductor lasers exposed to strong feedback from an external grating. The frequency range of stable single mode oscillation is found to depend on the offset between the resonance frequency of the solitary laser and the frequency of maximum reflection from the grating.

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Ground Separation Test to Verify Separation Stability of External Fuel Tank (외부연료탱크의 분리 안정성 검증을 위한 지상 분리시험)

  • Kim, Hyun-gi;Hong, Seung-ho;Ha, Byung-geun;Kim, Sung-chan;Lee, Jun-won
    • Journal of Aerospace System Engineering
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    • v.16 no.3
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    • pp.99-104
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    • 2022
  • Aircraft pylon connects the engine or external stores to the main wing, and transfers the load acting on the pylon to the main structure of the aircraft. In particular, it should perform the function of separating the external store mounted on the pylon in case of emergency or mission performance. At this time, if the separation of the external store is not performed properly due to peripheral air flow or functional problems during the separation process of the external store, it may seriously impact the survivability of the aircraft. For this reason, to apply an external attachment to an aircraft, it is necessary to prove the stability of the external attachment in the separation situation in advance. In this paper, we present the result of the ground separation test performed to confirm that the external fuel tank, which is an external attachment, can be safely separated from the pylon. As a result of the test, the separation movement of the external fuel tank was measured with a high-speed camera, and the stability of the separation of the external fuel tank from the pylon were confirmed through the ground separation test. Additionally, the test result provides basic data for the stability evaluation of the separation of external attachments in actual aircraft.

Stable Haptic Display Based on Coupling Impedance for Internal and External Forces

  • Kawai, Masayuki;Yoshikawa, Tsuneo
    • Transactions on Control, Automation and Systems Engineering
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    • v.4 no.1
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    • pp.2-8
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    • 2002
  • This paper discusses haptic display for grasping a virtual object by two fingers. Much research has been done on fundamental analysis for stability of haptic display. But it is difficult to apply the results immediately to grasping situations by two fingers, since the studies usually deal with a single device and a single object and the fingertip force in grasping situations has two components, internal and external components. The conventional methods, which specify the coupling impedance at each contact point separately, have no other alternative but to specify the impedance for the sum of the internal and external components. So even if only the impedance for the external force should be changed, the impedance for the internal force is also changed at the same time. In this paper, a new method, in which the coupling impedance is specified separately for the internal and external forces, is proposed and the stability of the proposed method is discussed using passivity analysis for 1 -DOF(Degree-Of-Freedom) system. Finally, some experiments are performed to study the effects of the proposed method.

Dynamic Stability during Transportation of Bridge Caisson (교량 케이슨 운송의 동적 안정성 고찰)

  • Jo, Chul-Hee;Kim, Sung-Jun;Cheong, Hyun
    • Journal of Ocean Engineering and Technology
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    • v.23 no.1
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    • pp.104-108
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    • 2009
  • As the demands of ocean resource development increase, many offshore structures are required. To cope with the active ocean developments, many types of construction methods have been applied for offshore facilities, including oil, gas and harbors. One of the challenges is to transport and install the heave bridge caisson. Several construction methods are well understood. However, for the sake of safety and reliability, the F/D installation method can be utilized. While the caisson is carried by an F/D, the mooring force of the tug boat and the structure stability from exiting motions in the dock should be checked against external loadings and sea conditions. The external loads can be classified with wind force, current force, and wave force. In the stability analysis, transportation velocity and draft of F/D are important factors. The dynamic stability and hook load for crane barge installation for the same caisson are also studied. Considering external loads and dominant factors, the stability of caisson during transportation has been investigated.

A Case Study on Design of Geosynthetic-Reinforced Segmental Retaining Walls (다단식 보강토 옹벽 설계사례에 관한 고찰)

  • Park, Si-Sam;Cho, Sam-Deok;Park, Du-Hee;Chang, Ki-Soo
    • Proceedings of the Korean Geotechical Society Conference
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    • 2008.10a
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    • pp.168-175
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    • 2008
  • The method of reinforced earth walls has grown remarkably and the frequency of utilization has been increased on a national scale thereafter introduced in the middle 1980s in Korea. Furthermore the construction case of the extensive Geosynthetic-Reinforced Segmental Retaining Walls had been increased. Currently, the design criterion of FHWA and NCMA mainly used in Korea suggest determining the horizontal distance of the upper/lower retaining wall based on the study results of the internal stability and the external stability of Segmental Retaining Walls but in many cases are not suitable for the actual situation in Korea. Therefore, in this study reviewed the design criterion of Geosynthetic-Reinforced Segmental Retaining Walls, performed the internal and external stability in Paju, Gyeonggi-do based on the design criterion of FHWA and NCMA, suggested the modified design criterion of FHWA with analyzing the results, and performed the stability analysis for the internal and external stability and the compound failure. Moreover for the confirmation of the modified FHWA design standard, the suggestion and the analysis of the numerical analysis approaching method using shear strength reduction technique were performed and the design cases utilized the modified FHWA design standard based on the study analysis were introduced.

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