• Title/Summary/Keyword: Stability Limits

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Physical properties and color stability of injection-molded thermoplastic denture base resins

  • Song, So-Yeon;Kim, Kyoung-Soo;Lee, Jeong-Yol;Shin, Sang-Wan
    • The Journal of Advanced Prosthodontics
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    • v.11 no.1
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    • pp.32-40
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    • 2019
  • PURPOSE. The purpose of this study was to compare mechanical and physical properties of injection-molded thermoplastic denture base resins. MATERIALS AND METHODS. In this study, six commercially available products (VA; Valplast, LC; Lucitone, ST; Smiltone, ES; Estheshot-Bright, AC; Acrytone, WE; Weldenz) were selected from four types of thermoplastic denture base materials (Polyamide, Polyester, Acrylic resin and Polypropylene). The flexural properties and shore D hardness have been investigated and water sorption and solubility, and color stability have evaluated. RESULTS. For the flexural modulus value, ES showed the highest value and WE showed significantly lower value than all other groups (P<.05). Most of experimental groups showed weak color stability beyond the clinically acceptable range. CONCLUSION. Within the limits of this study, thermoplastic denture base resin did not show sufficient modulus to function as a denture base. In addition, all resins showed discoloration with clinical significance, and especially polyamides showed the lowest color stability.

Analysis of Dynamic Instability in a Variable-reluctance Stepping Motor Operated on Frequency-modulated Supply (주파수변조 구동에 의한 가변릴럭턴스 스텝핑모우터의 불안정 해석)

  • Kwon, Yong-Soo
    • Proceedings of the KIEE Conference
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    • 1994.07a
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    • pp.114-118
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    • 1994
  • A comprehensive analytical study of frequency-modulated supply of the dynamic instability in a variable-reluctance stepping motor, is described. It is shown that stability can be achieved by frequency modulation provided that the phase displacement between the modulating signal and the rotor velocity oscillation lies between certain limits. A simplified expression is derived. based on the assumption of high inertia. This model is used to obtain a qualitative understanding of how frequency modulation influences the dynamic stability of the variable-reluctance motor.

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Development of ILSAC GF3 Gasoline Engine Oil (ILSAC GF3 가솔린엔진유 개발)

  • 류재곤;조연근;문우식
    • Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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    • 2001.06a
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    • pp.143-148
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    • 2001
  • ILSAC GF 3/API SL specification will be adopted in July 2001. The background and characteristics of GF3 specification is reviewed. GF3 specification consists of five new engine tests, two new bench tests and new limits on three bench tests currently used to define ILSAC GF-2. GF 3 engine oil shows good performance compared to GF2 engine oil in fuel efficiency, protecting ability the emission catalyst and high temperature oxidation stability.

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Assessment of Total Transfer Capability Using IPLAN: An Application of UPFC for Total Transfer Capability Enhancement

  • Lee Byung Ha;Kim Jung-Hoon;Kwak No-Hong;Lee Woon-Hee
    • KIEE International Transactions on Power Engineering
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    • v.5A no.3
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    • pp.244-251
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    • 2005
  • Power transfer capability has been recently highlighted as a key issue in many utilities. It is determined by the thermal stability, dynamic stability and voltage stability limits of generation and transmission systems. In particular, voltage stability affects power transfer capability to a great extent in many power systems. This paper presents a tool for determining total transfer capability from a static voltage stability viewpoint using IPLAN, which is a high level language used with the PSS/E program. The tool was developed so as to analyze static voltage stability and to determine the total transfer capability between different areas from a static voltage stability viewpoint by tracing stationary behaviors of power systems. A unified power flow controller (UPFC) is applied for enhancing total transfer capability between different areas from the viewpoint of static voltage stability. Evaluation of the total transfer capability of a practical KEPCO power system is performed from the point of view of static voltage stability, and the effect of enhancing the total transfer capability by UPFC is analyzed.

Structural Properties of Steel-glulam Composite Column

  • Jang, Sang-Sik;Kim, Yun-Hui;Shin, Il-Joong
    • Journal of the Korean Wood Science and Technology
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    • v.38 no.5
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    • pp.399-404
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    • 2010
  • A new green home designed to save money while at the same time saving the environment with some of the finest green features available in the market. Composite column composed of structural steel and structural glued laminated timber is avery Eco-friendly building products for design building because that use recycled or second hand. For compare to compressive strength of structural glued laminated timber (glulam), structural steel, and composite column (steel-glulam), tested compressive strength of each specimen. 1) structural glued laminated timber : Theoretical compressive strength is 151.6 kN similar to elastic limits. 2) structural steel (H type) : Theoretical compressive strength is 148.2 kN little under the elastic limits. 3) structural steel (D type) : Theoretical compressive strength is 147.3 kN upper than the elastic limits. 4) composite column : Actual elastic limits are about 600 kN. Result in, composite column improve compressive strength of Structural steel column and provide structural stability of the building.

Experiences of Participation in Dementia Prevention Program for Older Adults in Nursing Homes (요양시설노인의 치매예방 프로그램 참여 경험)

  • Lim, Sun Ok;Jo, Hyun Mi
    • The Korean Journal of Rehabilitation Nursing
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    • v.19 no.2
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    • pp.128-137
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    • 2016
  • Purpose: This study was designed to describe the experiences of dementia prevention program for older adults in nursing homes. Methods: Four focus group interviews (FGI) after the program were conducted with 35 participants. All interviews were audio-taped and transcribed verbatim. The transcribed data were analyzed by Colaizzi's phenomenological method. Results: Four themes emerged as a result of analysis. Participants without dementia reported "I don't have dementia yet." This statement probably reflects ignoring potential dementia. Motivation for participating the dementia prevention program were to reduce boredom, to enjoy exercising and communicating with others, and to follow group activities. Participants reported the positive effects of the program; (a) benefits from the repeating learned activities; (b) improvements of memory and emotional stability. A few participants reported their inability to follow the program due to physical and environmental limits. However, other participants reported their efforts to overcome physical limits and perform the activities regardless their limits. People who performed the activities with physical limits reported that their self-satisfaction was increased. Conclusion: Results of this study showed that participants without dementia were able to actively participate in dementia prevention programs and showed memory, emotional and behavioral improvements. Therefore, these findings can be used for developing customized dementia prevention programs in nursing homes.

Effects of Postural Balance at Game-based Visual Feedback Training of the Elderly (고령자의 게임기반 시각피드백 훈련에 따른 자세 균형 효과)

  • Yi, Jeong-Won;Yu, Mi;Lee, Ah-Reum;Kwon, Tae-Kyu
    • The Journal of the Korea Contents Association
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    • v.13 no.10
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    • pp.9-18
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    • 2013
  • In this paper, we analyzed the effects of game-based visual feedback training on postural balance control in young adults and older adults. We provided postural balance training by 23 young adults and 14 older adults and for four weeks in fifth minute a day and three days a week using IBalance(Cybermedic Inc., Korea). We evaluated the ability of postural balance using balance SD(Biodex, medicalscience Inc., USA) for the validation of game contents based on visual feedback training program. The results showed that postural stability and limits of stability of young adults and older adults were improved significantly before and after the training(p<0.05). Thus, the games of postural balance encouraged anterior, posterior, medial, lateral and multidirectional weight shifting regarding postural balance. Our study indicates that postural balance training of visual feedback based game could be adapted for improving postural balance. Moreover, we could develope of game contents for individuals and various ages for effective application of this game-based visual feedback training.

An Adaptive Tracking Control for Robotic Manipulators based on RBFN

  • Lee, Min-Jung;Jin, Tae-Seok
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • v.7 no.2
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    • pp.96-101
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    • 2007
  • Neural networks are known as kinds of intelligent strategies since they have learning capability. There are various their applications from intelligent control fields; however, their applications have limits from the point that the stability of the intelligent control systems is not usually guaranteed. In this paper we propose an adaptive tracking control for robot manipulators using the radial basis function network (RBFN) that is e. kind of neural networks. Adaptation laws for parameters of the RBFN are developed based on the Lyapunov stability theory to guarantee the stability of the overall control scheme. Filtered tracking errors between actual outputs and desired outputs are discussed in the sense of the uniformly ultimately boundedness(UUB). Additionally, it is also shown that parameters of the RBFN are bounded. Experimental results for a SCARA-type robot manipulator show that the proposed adaptive tracking controller is adaptable to the environment changes and is more robust than the conventional PID controller and the neuro-controller based on the multilayer perceptron.

A study on stability of feeder system considering driving of railway vehicle and rail conditions (철도차량 운행 및 선로조건에 따른 교류 급전시스템의 안정성 연구)

  • Kim, Jae-Moon;Kim, Yang-Su;Lee, Jong-Sung
    • Proceedings of the KIEE Conference
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    • 2011.07a
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    • pp.2213-2214
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    • 2011
  • It is important to consider power stability in case of design and construction of a substation at railroad because a train is operated by electricity and tains are drived simultaneous at the same section. This paper described stability of feeder system considering driving conditions and railroad conditions of train which is drived. Simulation tool, TOM(Train Operations Model) software is used to ensure stability of feeder system. As results of simulation, feeder voltage source is in limits on driving operation dia of trains.

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Analysis of stability on steel D&I can (Steel D&I Can의 안정성 해석)

  • Cho, S.J.;You, C.S.;Jung, S.W.;Park, H.C.;Hwang, W.;Han, K.S.
    • Proceedings of the KSME Conference
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    • 2001.11a
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    • pp.471-476
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    • 2001
  • The main object of this study is to develop a reliable FEM simulation technique for stability test using ABAQUS software and to clarify the effect of base profile of a steel D&I(drawn and ironed) can on the dome reversal pressure. For the can after body making simulation, two kind of stability test, dome buckle test and axial crush test are performed. The factors studied in the base profile on the dome reversal pressure are the base diameter, the rim radius, the dome shoulder radius, the dome radius and the dome depth. Within the limits before the occurrence of normal snap-through buckling of dome, the dome reversal pressure is improved by decreasing the base diameter, increasing the dome depth or increasing the dome shoulder depth.

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