• 제목/요약/키워드: stress recovery

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Dimensional Stability of wool Fabrics Treated with Multifunctional Epoxide and Reactive Silicone Polymers

  • Moon, Su-Jin;Kang, Tae-Jin
    • 한국섬유공학회:학술대회논문집
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    • 한국섬유공학회 1998년도 가을 학술발표회논문집
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    • pp.207-210
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    • 1998
  • Among the common textile fibers, wool has excellent wrinkle recovery. However, absorbed moisture plasticizes the structure and increases the rate of stress relaxation during wear deformation. Therefore, the wrinkle recovery of wool deteriorates under very high-humidity conditions and is of particular concern in men's lightweight suits, where the trend is toward wool fabrics of lightweight and bright color in which the wrinkles are emphasized. (omitted)

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에너지재생 수동스너버를 갖는 고역율 부스트 정류기 (High-Power-Factor Boost Rectifier with a Passive Energy Recovery Snubber)

  • 김만고;백승호
    • 전력전자학회:학술대회논문집
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    • 전력전자학회 1998년도 전력전자학술대회 논문집
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    • pp.428-432
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    • 1998
  • A passive energy recovery snubber for high-power-factor boost rectifier, in which the main switch is implemented with a MOSFET, is described in terms of the equivalent circuits that are operational during turn-on and turn-off sequences. The main switch combined with proposed snubber can be turned on with zero current and turned off at limited voltage stress. The high-power-factor boost rectifier with proposed snubber is implemented, and the experimental results are presented to confirm the validity of proposed snubber.

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폴리에틸렌옥사이드 수용액의 유변학적 특성 평가 - 크리프 및 크리프 회복 - (Rheological, Characterization of Aqueous Poly(Ethylene Oxide) Solutions - Creep and Creep Recovery -)

  • 장갑식;김태훈;박영훈;송기원
    • 한국섬유공학회:학술대회논문집
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    • 한국섬유공학회 2001년도 가을 학술발표회 논문집
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    • pp.175-178
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    • 2001
  • 일반적으로 점탄성 거동을 나타내는 고분자 액체의 전단유동특성(shear flow properties)을 평가하기 위하여 정상전단(steady shear), 동적전단(dynamic shear), 응력완화(stress relaxation) 그리고 크리프(creep) 및 크리프 회복(creep recovery) 실험 등이 활용되고 있다[1], 이때 영전단점도(zero shear viscosity)와 정상상태 회복 컴플라이언스(steady-state recoverable compliance)는 정상상태(steady state)에서 얻어지는 물리량으로, 각 실험방법으로부터 직접적 또는 간접적으로 측정이 가능하다. (중략)

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Cost-effective Single Board PDP Sustaining Driver with Dual Resonant Method

  • Lee, Jun-Young
    • Journal of Power Electronics
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    • 제9권1호
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    • pp.93-99
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    • 2009
  • A new plasma display panel sustaining driver using single side sustaining technique with a dual resonant method is proposed in this paper. Since this circuit enables to keep device voltage stress same as the prior circuit, it can be a low cost circuit compared to a conventional driver. To integrate the sustaining function into one side with a single power source in the driver, a charge pump method is adopted to make negative sustaining voltage and to achieve dual resonant energy recovery on the sustaining modes.

Internal Service Recovery's Influence on Frontline Service Employees' Satisfaction and Loyalty

  • Gong, Taeshik
    • Asia Marketing Journal
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    • 제17권2호
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    • pp.39-62
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    • 2015
  • Relatively little studies have investigated employee recovery from internal service failure, especially from the employees' perspective. When handling customer complaints, employees must not only deal with legitimate customer demands after a service failure, such as providing an apology, rectifying the problem, and offering compensation, but they must also manage illegitimate dysfunctional customers, who may yell, threaten, and even physically harm the employee. These negative experiences can have strong effects, and employees can exhibit higher levels of stress such as burnout and emotional labor, which have been linked to dissatisfaction, tension and anxiety, reduced performance and effectiveness, and a greater propensity to leave the firm, ultimately leading to negative financial consequences for the firm. These conditions result in internal service failure and create the need to recover employees-in other words, internal service recovery. However, little research has examined this issue so far. The purpose of the current study, therefore, is to investigate the relationship between internal service recovery and employee outcomes. A pre-test, post-test between-subjects experimental design was developed. Participants were 166 part-time students who were working full-time. The average age of the participants was 36.74 years, and 57.50% of them were female. The average length of employment was 13 years. Participants were randomly assigned to one of four groups of approximately equal size. Three of the groups were subjected to an experimental situation involving an internal service failure, while one group was not exposed to failure, thereby acting as a control group. This study contributes to the service marketing literature in several ways. First, the study extends service failure and/or recovery research by examining recovery in an employee context. Second, this study attempts to measure internal service recovery and to empirically demonstrate its relationship to employee outcomes. Third, this investigation emphasizes the managerial importance of internal service recovery. For example, understanding the nature of the relationships between internal service recovery and its consequences can improve the effectiveness and efficiency of managers' resource allocation decisions.

Automated detection of panic disorder based on multimodal physiological signals using machine learning

  • Eun Hye Jang;Kwan Woo Choi;Ah Young Kim;Han Young Yu;Hong Jin Jeon;Sangwon Byun
    • ETRI Journal
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    • 제45권1호
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    • pp.105-118
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    • 2023
  • We tested the feasibility of automated discrimination of patients with panic disorder (PD) from healthy controls (HCs) based on multimodal physiological responses using machine learning. Electrocardiogram (ECG), electrodermal activity (EDA), respiration (RESP), and peripheral temperature (PT) of the participants were measured during three experimental phases: rest, stress, and recovery. Eleven physiological features were extracted from each phase and used as input data. Logistic regression (LoR), k-nearest neighbor (KNN), support vector machine (SVM), random forest (RF), and multilayer perceptron (MLP) algorithms were implemented with nested cross-validation. Linear regression analysis showed that ECG and PT features obtained in the stress and recovery phases were significant predictors of PD. We achieved the highest accuracy (75.61%) with MLP using all 33 features. With the exception of MLP, applying the significant predictors led to a higher accuracy than using 24 ECG features. These results suggest that combining multimodal physiological signals measured during various states of autonomic arousal has the potential to differentiate patients with PD from HCs.

리올러지 모델을 이용한 열적 기계적 변형 거동 모사 (A Description of Thermomechanical Behavior Using a Rheological Model)

  • 이금오;홍성구;이순복
    • 대한기계학회논문집A
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    • 제30권7호
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    • pp.757-764
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    • 2006
  • Isothermal cyclic stress-strain deformation and thermomechanical deformation (TMD) of 429EM stainless steel were analyzed using a rheological model employing a bi-linear model. The proposed model was composed of three parameters: elastic modulus, yield stress and tangent modulus. Monotonic stress-strain curves at various temperatures were used to construct the model. The yield stress in the model was nearly same as 0.2% offset yield stress. Hardening relation factor, m, was proposed to relate cyclic hardening to kinematic hardening. Isothermal cyclic stress-strain deformation could be described well by the proposed model. The model was extended to describe TMD. The results revealed that the hi-linear thermomechanical model overestimates the experimental data under both in-phase and out-of-phase conditions in the temperature range of $350-500^{\circ}C$ and it was due to the enhanced dynamic recovery effect.

Conformational changes of short, discrete Rouse chain during creep and recovery processes

  • Watanabe, Hiroshi;Inoue, Tadashi
    • Korea-Australia Rheology Journal
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    • 제16권2호
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    • pp.91-99
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    • 2004
  • For the Rouse chain composed of infinite number of beads (continuous limit), conformational changes during the creep and creep recovery processes was recently analyzed to reveal the interplay among all Rouse eigenmodes under the constant stress condition (Watanabe and Inoue, Rheol. Acta, 2004). For completeness of the analysis of the Rouse model, this paper analyzes the conformational changes of the discrete Rouse chain having a finite number of beads (N = 3 and 4). The analysis demonstrates that the chain of finite N exhibits the affine deformation on imposition/removal of the stress and this deformation gives the instantaneous component of the recoverable compliance, $J_{R}$(0) = 1/(N-l)v $k_{B}$T with v and $k_{B}$ being the chain number density and Boltzmann constant, respectively. (This component vanishes for N\longrightarrow$\infty$.) For N = 2, it is known that the chain has only one internal eigenmode so that the affinely deformed conformation at the onset of the creep process does not change with time t and $J_{R}$(t) coincides with $J_{R}$(0) at any t (no transient increase of $J_{R}$(t)). However, for N$\geq$3, the chain has N-l eigenmodes (N-l$\geq$2), and this coincidence vanishes. For this case, the chain conformation changes with t to the non-affine conformation under steady flow, and this change is governed by the interplay of the Rouse eigenmodes (under the constant stress condition). This conformational change gives the non-instantaneous increase of $J_{R}$(t) with t, as also noted in the continuous limit (N\longrightarrow$\infty$).X>).TEX>).X>).

VOCs의 분리 및 회수를 위한 PEI-PDMS 중공사 복합막의 내용매성 및 기체 투과 특성 (Solvent Resistance and Gas Permeation Property of PEI-PDMS Hollow Fiber Composite Membrane for Separation and Recovery of VOCs)

  • 김세종;이충섭;고형철;하성용;남상용;임지원;최휘문
    • 멤브레인
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    • 제22권1호
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    • pp.54-61
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    • 2012
  • VOCs의 분리 및 회수를 위해 PEI 고분자를 이용하여 상분리법으로 중공사 지지체 분리막을 제조하였고 PDMS 고분자를 코팅하여 PEI-PDMS 중공사 복합막을 제조하였다. 제조된 기체 분리막의 특성을 알아보기 위하여 산소와 질소를 이용하여 순수 기체 투과도를 측정하였으며, xylene, ethyl benzene, toluene, cyclohexane을 이용하여 stage cut과 feed 농도 변화에 따른 투과성능을 측정하였다. 또한 VOCs에 대한 내용매성을 알아보기 위하여 DMA을 이용하여 용매 함침 시간에 따른 stress-strain 특성을 알아보았다. 산소와 질소의 순수 투과도는 각각 63 GPU와 30 GPU를 나타내었고, stage cut이 증가할수록 permeate VOCs 농도는 감소하는 경향을 나타내었다. Recovery efficiency의 경우 permeate 농도와는 반대로 state cut이 증가할수록 증가하는 경향을 나타내었다. DMA 인장 테스트 결과 stress는 11.93 MPa, strain은 13.52%로 측정되었다.

대학 축구선수에서 일회성 무산소 운동에 따른 운동 유발성 스트레스 반응의 변화 (Changes of Exercise-induced Stress Response with an Acute Anaerobic Exercise in Elite Soccer Players of University)

  • 가기현;권대근;박재용;강준용;송영주
    • 운동영양학회지
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    • 제13권3호
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    • pp.211-216
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    • 2009
  • This study was conducted to investigate the changes of exercise-induced stress response with acute anaerobic exercise in elite soccer players of university. The subjects were divided into elite soccer players of university (SG, n=10) and control group (CG, n=10). Subjects were tested three consecutive Wingate test for 30 seconds involving 2 times of 3 mins of resting time. In addition, whole blood and capillary blood were collected at rest, immediately post-exercise and 60 mins. of recovery time. Obtained results were as follows: Evaluated mean power and peak power of SG group was significantly higher than that of CG group in the all phase of Wingate test, respectively (p<.01). Although resting serum TG, TC, HDLC levels were not significant difference between SG and CG group, resting serum glucose of SG group was significantly lower than that of CG group. In addition, serum CRP levels of SG group were significantly lower than that of CG group at rest, immediately post-exercise and 60 mins of recovery time, respectively (p<.01). In serum cytokines, in spite of no significant differences in IL-1β levels between SG and CG group, IL-6 levels of SG group were significantly lower than that of CG group at immediately post-exercise and 60 mins. of recovery time, respectively (p<.05, p<.01). From these results, long-term combination training have a crucial role in amelioration of acute exerciseinduced stress response in elite soccer players.