• Title/Summary/Keyword: stress recovery

Search Result 659, Processing Time 0.025 seconds

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

  • Moon, Su-Jin;Kang, Tae-Jin
    • Proceedings of the Korean Fiber Society Conference
    • /
    • 1998.10a
    • /
    • pp.207-210
    • /
    • 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)

  • PDF

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

  • 김만고;백승호
    • Proceedings of the KIPE Conference
    • /
    • 1998.07a
    • /
    • pp.428-432
    • /
    • 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.

  • PDF

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

  • 장갑식;김태훈;박영훈;송기원
    • Proceedings of the Korean Fiber Society Conference
    • /
    • 2001.10a
    • /
    • pp.175-178
    • /
    • 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)

  • PDF

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

  • Lee, Jun-Young
    • Journal of Power Electronics
    • /
    • v.9 no.1
    • /
    • pp.93-99
    • /
    • 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
    • /
    • v.17 no.2
    • /
    • pp.39-62
    • /
    • 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
    • /
    • v.45 no.1
    • /
    • pp.105-118
    • /
    • 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.

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

  • Lee Keum-Oh;Hong Seong-Gu;Lee Soon-Bok
    • Transactions of the Korean Society of Mechanical Engineers A
    • /
    • v.30 no.7 s.250
    • /
    • pp.757-764
    • /
    • 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
    • /
    • v.16 no.2
    • /
    • pp.91-99
    • /
    • 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>).

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

  • Kim, Se-Jong;Lee, Chung-Seop;Koh, Hyung-Chul;Ha, Seong-Yong;Nam, Sang-Yong;Rhim, Ji-Won;Choi, Whee-Moon
    • Membrane Journal
    • /
    • v.22 no.1
    • /
    • pp.54-61
    • /
    • 2012
  • To separate and recover of VOCs, supporting membranes using PEI were prepared by phase separation method and it was coated with PDMS to prepare PEI-PDMS hollow composite membrane. To investigate characteristic of prepared membrane, pure gas permeability was measured using oxygen and nitrogen, the stage cut and permeance property with feed concentration were evaluated using xylene, ethyl benzene, toluene and cyclohexane. Also, to check solvent resistance on VOCs, stress-strain property of membrane with immersion time in solvent were measured by DMA. The permeance value of $O_2$ and $N_2$ showed 63 GPU and 30 GPU respectively. Permeated VOCs concentration was decreased with increasing stage cut. But, conversely, recovery efficiency that was increased with increasing stage cut. As a result of DMA test, the stress and strain were 11.93 MPa and 13.52%, respectively.

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

  • Ka, Kihyun;Kwon, Daekeun;Park, Jaeyong;Kang, Junyong;Song, Youngju
    • Korean Journal of Exercise Nutrition
    • /
    • v.13 no.3
    • /
    • pp.211-216
    • /
    • 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.