• Title/Summary/Keyword: Stability degree

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A Study on the Predictability of the Maternal Attitude from Preschooler's Temperament and Mother's Mental Stability (유아 기질과 어머니 심리적 안정성의 양육태도 설명력에 관한 연구)

  • 최영희
    • Journal of the Korean Home Economics Association
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    • v.33 no.5
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    • pp.187-196
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    • 1995
  • This study was performed was performed to identify the predictability of maternal attitude from infant's temperament and mother's mental stability. It was focused on the comparison of the degree of predictability between infant's temperament and mother's mental stability. Data were collected from sixty-five mothers of infants. Mother's affective attitude was explained by both the maternal mental stability and the infant's temperament. After controlling the effect of mental stability, infant's temperament could explain the affective attitude. This result meant that infant's temperament showed the powerful effect on the maternal affective attitude. However, maternal controlling attitude was only explained by her mental stability but not by infant's temperament. This meant that infant's temperament could not explain mother's controlling behavior. However, interactive effect between infant's sex and temperament was found in the controlling attitude. Mothers showed more controlling attitude toward the difficult boys but not toward the difficult girls.

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Stability Control of Four-Wheel Steering Vehicles (4WS 차량의 안정성 제어)

  • Ko, Young-Eun;Song, Chul-Ki
    • Transactions of the Korean Society of Automotive Engineers
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    • v.16 no.3
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    • pp.127-136
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    • 2008
  • Vehicle stability is a very important subject in vehicle design and control, because vehicle safety is closely dependent upon its dynamic stability. The control logic for four-wheel steering(4WS) systems, in which maintaining at least the specified stability region is the control objective, was constructed using the simplified vehicle model of 3 degree-of-freedoms. The improvement of vehicle stability was verified through computer simulations for the slalom and the double lane change maneuver using the multi-body dynamic model in MSC.ADAMS.

A Study on the Stability and Behavior of upward Soil-nailing (상향으로 설치된 쏘일네일링의 안정성 및 거동에 관한 연구)

  • Kim, Jae-Yoon;Lee, In;Choi, Geun-Hyeok;Kim, Hong-Taek
    • Proceedings of the Korean Geotechical Society Conference
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    • 2009.03a
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    • pp.1086-1091
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    • 2009
  • The purpose of this study is to provide the technical information of the stability change and behaviour characteristics in case upward direction of soil nailing is installed. Generally, the soil nailing which installed in case of vertical excavation or for the purpose of the slope stability is installed between 5 to 15 degree of downward direction. The downward direction of the soil nailing method has lots of advantages such as the increase of the stability, the convenience of the grout compared to upward direction of soil nailing. Even though the upward direction of the soil nailing has the disadvantages in terms of the stability and the grout construction, horizontal displacement tends to be decreased.

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Human Workers' Stability-Maintaining Capabilities on A Tiltable Stability Platform (안정판 위에서의 직립자세시 평형유지 특성)

  • 최재남;임현교
    • Journal of the Korean Society of Safety
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    • v.12 no.2
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    • pp.146-152
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    • 1997
  • The number of accidents due to slipping, falling and awkward postures are estimated to account for over forty percent of annual industrial accidents in Korea. To prevent such accidents, stability-maintaining capabilities of workers should be understood before any other approach. This research was aimed to analyze capabilities of the workers with the help of yours male students maintaining standing postures on a tiltable stability platform. The experimental result showed that tilting direction, height of pivoting point, and permissible degree of swaying made significant effects on stability-maintaining duration. Besides, humans are more capable of maintaining their standing body postures on a platform tiltable fore and aft rather than or one tiltable sideways. The number of falling or tripping supported this phenomenon. A mechanical and physical discussion on the stability was added.

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Mechanical Characteristics of Weathered Granite Soils for Degree of Weathering and Saturation (풍화도과 포화도에 따른 화강토의 역학적 특성)

  • Lim, Seongyoon;Song, Changseob;Kim, Myeonghwan
    • Journal of The Korean Society of Agricultural Engineers
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    • v.57 no.3
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    • pp.93-100
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    • 2015
  • The object of this paper is to study the shear characteristics of the weathered granite soil. To this end, a series of consolidated undrained triaxial compression tests are carried out to investigate the shear parameters-cohesion and internal friction angle-for the degree of saturation and degree of weathering. From the results, it is found that the shear parameters of weathered granite soil are influenced on the degree of saturation, degree of weathering and disturbance. Especially, internal friction angle is more influenced on the upper factors than cohesion. And shear parameters are more acted on the degree of saturation than the degree of weathering in the test range. It is, therefore, recommended that must be considered the conditions of granite soil-degree of saturation, degree of weathering and disturbance etc-in case of the calculation of bearing capacity, stability analysis and other designs with shear parameters.

Determining the Priority of Investment for Remedial Works of Slopes (사면관리를 위한 재원의 투자 우선 순위 평가)

  • 김상규;류지협;구호본;정하익;윤수호
    • Proceedings of the Korean Geotechical Society Conference
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    • 1999.03a
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    • pp.269-276
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    • 1999
  • The program ESRAS Ver 0.5 that can assess the risk of slopes by means of fuzzy inference is developed in this paper. The results of assessment involve the degree of stability of slopes, the possible travel distance of the soil mass being failed, and anticipated loss of life and properties. With this program, vulnerable slopes can be managed most effectively and the fuzzy inference is used to express quantitatively the judgement of an expert and the uncertainty of slope stability. The fuzzy rule base is composed of an evaluation list for slope stability together with the experience of an expert. This program has been examined for 88 slopes which have been failed or shown a possibility of failure. With this examination, the standards to assess the stability of slopes can be presented and it is proven that this is particularly useful in determining the priority of investment for remedial works of slopes.

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A Study on Integrated Control of AFS and ESP for the improvement of vehicle handing performance (차량 주행성능 향상을 위한 AFS 와 ESP 의 협조제어에 관한 연구)

  • Park In-Hye;Park Ki-Hong
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2005.06a
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    • pp.511-514
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    • 2005
  • This paper propose an advanced control strategy to improve vehicle handling and directional stability by integrating Active Front Steering(AFS) with Electronic Stability Program(ESP) . The effect of the integrated control system on the vehicle handling characteristics and directional stability is studied through a close loop computer simulation of and eight degree of freedom nonlinear vehicle model and driver model. Simulation results confirm the effectiveness of the proposed control system and the overall improvements in vehicle handling and directional stability

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Robust Stability of Two-Degrees-of-Freedom Servosystem with Stricture and Unstructured Uncertainties

  • Kim, Young-Bok
    • Journal of Mechanical Science and Technology
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    • v.14 no.11
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    • pp.1198-1205
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    • 2000
  • A two-degrees-of-freedom servosystem for step-type reference signals has been preposed, in which the integral compensation is effective only when there is a modeling error or a disturbance input. this paper considers robust stability of the servosystem incorporating an observer against both structured and unstructured uncertainties of the plant. A condition is obtained as a linear matrix inequality, under which the servosystem is robustly stable independently of the gain of the integral compensator. This result implies that we can tune the gain to achieve a desirable transient response of the servpsystem preserving robust stability. An example is presented to demonstrate that under the robust stability condition, the transient response can be improved by increasing the gain of the integral compensator.

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Improving Light Stability of Natural Rubber Latex Foam

  • Shim, Chang Su;Oh, Jeong Seok;Hong, Chang Kook
    • Elastomers and Composites
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    • v.50 no.2
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    • pp.81-86
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    • 2015
  • In this study, natural rubber latex foam was prepared in order to replace commercialized polyurethane foams as a car seat material. Physical properties of the latex foam were investigated and the light stability was improved. The latex foam was mixed in an aqueous solution state, and the degree of foaming and the accelerator ratios were appropriately controlled. Tensile properties, hysteresis and dynamic mechanical properties of the latex foam were measured to compare with those of polyurethane foams. UV light absorbers and radical scavengers were added for improving light stability of the latex foam. Xenon lamp test was conducted to investigate the effects of the reagents on light stability. Our results revealed that the prepared latex foam including a light absorber with an antioxidant showed excellent light stable performances.

Application of Derivative State Constrained Optimal $H_2$ Controller for Disk Drive Read System

  • N., Puttamaoubon;A., Numsomran;T., Trisuwannawat;K., Tirasesth;M., Iida
    • 제어로봇시스템학회:학술대회논문집
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    • 2003.10a
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    • pp.1410-1413
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    • 2003
  • This paper presents the design technique for controlling the oscillation in the Disk Drive Read System via Derivative State Constrained (DSC)-Optimal $H_2$ Controller. The Optimal $H_2$, DSC-Optimal $H_2$ and Incorporating of Stability Degree Specification DSC Optimal $H_2$ are discussed. The results among these schemes are compared to verify the merit of DSC that effectively suppresses the oscillation in oscillatory system. The suggestions of how to select the weights of optimal controls are given.

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