• Title/Summary/Keyword: repeated stress

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The Effect of Mind Awareness Records on Awareness of Imaginations, Decentering, Parenting stress and Subjective Well-bing: With a Focus on Parents of Adolescents (마음알아차리기 기록이 공상자각, 탈중심화, 양육스트레스 및 주관적 안녕감에 미치는 영향 : 청소년기 자녀를 둔 부모를 중심으로)

  • Jung, Hyun Gi;Sung, Seoung Yun
    • Journal of Family Relations
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    • v.20 no.4
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    • pp.73-103
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    • 2016
  • Objectives: The purpose of this study is to examine the effects of reading mind recording on awareness of imaginations, Method: Decentering, parenting stress and subjective well-being through comparing expressive writing. random assignment was performed on each 13 persons of a recording group (experimental group) and an expressive writing group (comparison group) for reading mind from 26 parents having adolescents. The experimental group conducted the reading of reading mind and the comparison group performed expressive writing twice a week for eight weeks, twenty minutes per time, and responded to four questions on thought arrangement after writing. The researcher participated in the groups once per week and an assignment was suggested once per week. Repeated Measurement Two-way Repeated Measures ANOVA was conducted to confirm the differences according to periods and groups for the data analysis method. In order to examine the changes according to periods, t-test was conducted on the pre- and post-test. Results: The findings are as follows: First, regarding awareness of imaginations and decentering, the reading mind recording group showed a significant result in repeated measurement. Second, the reading mind recording group showed a significant decrease in the pre- and post-t-test about parenting stress. Third, all the reading mind recording group and expressive writing group showed significant results about subjective well-being. Conclusions: This study is significant in that it verified the effectiveness of reading mind recording on awareness of imaginations, decentering and parenting stress, and proved the possibility as an oriental counseling model that considers the characteristics of our culture.

Analysis of Physiological Bio-information, Human Physical Activities and Load of Lumbar Spine during the Repeated Lifting Work (반복적인 들어올리기 작업시 작업자의 생체정보, 인체활동량 및 허리부하 분석)

  • Son, Hyun-Mok;SeonWoo, Hoon;Lim, Ki-Taek;Kim, Jang-Ho;Chung, Jong-Hoon
    • Journal of Biosystems Engineering
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    • v.35 no.5
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    • pp.357-365
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    • 2010
  • Workers in the agricultural industry have been exposed to many work-related musculoskeletal disorders. So, our objectives in this study were to measure and analyze worker's physiological bio-information to reduce musculoskeletal disorders in relation to agricultural works. We investigated worker's bio-information of physiological signals during the repeated lifting work such as body temperature, heart rate, blood pressure, physical activity, and heart rate variability. Moreover, we analyzed the workloads of lumbar spine during the repeated lifting work using the 3-axis acceleration and angular velocity sensors. The changes of body temperature was not significant, but the mean heart rate increased from 90/min to 116/min significantly during 30 min of repeated lifting work (p<0.05). The average worker's physical activity(energy consumption rate) was 206 kcal/70kg/h during the repeated lifting work. The workers' acute stress index was more than 80, which indicated a stressful work. Also, the maximum shear force on the disk (L5/S1) of a worker's lumbar spine in static state was 500N, and the maximum inertia moment was 139 $N{\cdot}m$ in dynamic state.

Antidepressant Effects of Gammakdaejo-Tang on Repeated Immobilization Stress in the Ovariectomized Female Rats

  • Park, Hyun-Jung;Shim, Hyun-Soo;Lee, Hye-Jung;Yun, Young-Ju;Shim, In-Sop
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.25 no.5
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    • pp.876-880
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    • 2011
  • Gammakdaejo-Tang (GMT) is a traditional oriental medicinal formula, a mixture of 3 crude drugs, and it has been clinically used for treating mild depressive disorders. The purpose of the study was to examine the effect of Gammakdaejo-Tang (GMT) on repeated stress-induced alterations of learning and memory on a passive avoidance test (PAT) test and also the anxiety-related behavior on the elevated pulse maze (EPM) in ovariectomized female rats. We assessed the changes in the reactivity of the cholinergic system by measuring the immunoreactive neurons of choline acetyltransferase (ChAT) in the hippocampus after behavioral testing. The rats were exposed to the immobilization (IMO) stress for 14 days (2hours/day), and Gammakdaejo-Tang (400 mg/kg, p.o.) was administered 30 min before IMO stress. Treatments with GMT caused significant reversals of the stress-induced deficits in learning and memory on a working memory test, and it also produced an anxiolytic-like effect on the EPM, and increased the ChAT reactivities (p<0.001, respectively). These results suggest that Gammakdaejo-Tang might prove to be an effective antidepressant agent.

The Effects of a Group Art Therapy on Job Stress and Burnout among Clinical Nurses in Oncology Units (집단미술치료가 암병동 간호사의 직무스트레스와 소진에 미치는 효과)

  • Jang, Ok Jeom;Ryu, Ui Jeong;Song, Hyun Jeong
    • Journal of Korean Clinical Nursing Research
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    • v.21 no.3
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    • pp.366-376
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    • 2015
  • Purpose: The purpose of this study was to evaluate the effects of a group art therapy on decreasing job stress and burnout of clinical oncology nurses. Methods: The study was conducted using a non-equivalent control group, non-synchronized design with repeated measures. A total of 29 clinical oncology nurses participated in the study; 15 were assigned in the experimental group, and 14 in the control group. Data were collected from May to July, 2014. The study questionnaires were administered in three different time points (pretest, 8th week, and 12th week). Data were analyzed using $x^2-test$, Fisher's exact test, t-test, paired t-test, and repeated measures ANOVA. Results: The first hypothesis "the experimental group with group art therapy will have lower job stress than that of the control group" was support (F=7.88, p=.003). The second hypothesis, "the experimental group will have lower burnout than that of the control group" was not statistically supported (F=1.80, p=.188). Conclusion: The findings of the study indicated that the group art therapy for oncology nurses may positively influence in decreasing job stress, which open a venue for developing a nursing intervention with group art therapy for clinical nurses in future.

Resilient Moduli of Sub-ballast and Subgrade Materials (강화노반 및 궤도하부노반 재료의 회복탄성계수)

  • Park, Chul-Soo;Choi, Chan-Yong;Choi, Choong-Lak;Mok, Young-Jin
    • Proceedings of the KSR Conference
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    • 2007.11a
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    • pp.1042-1049
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    • 2007
  • Recently, a theoretically-sound design approach, using an elastic multilayer model, is attempted in trackbed designs for the construction of high speed railways and new lines of conventional railways. In the elastic multilayer model, the stress-dependent resilient modulus($E_R$) is an important input parameter, that is, reflects substructure performance under repeated traffic loading. However, the evaluation method for resilient modulus using repeated loading triaxial test is not fully developed for practical purpose, because of costly equipment and the significantly fluctuated values depending on the testing equipment and laboratory personnel. In this study, the paper will present an indirect method to estimate the resilient modulus using dynamic properties. The resilient modulus of crushed stone, which is the typical material of sub-ballast, was calculated with the measured dynamic properties and the range of stress level of the sub-ballast, and approximated with the power model combined with bulk and deviatoric stresses. The resilient modulus of coarse grained material decreases with increasing deviatoric stress at a confining pressure, and increases with increasing bulk stress. Sandy soil(SM classified from Unified Soil Classification System) of subgrade was also evaluated and best fitted with the power model of deviatoric stress only.

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Influence of Repeated Loading, Alternation of Temperature and Initial Condition on the Change of Strizctural and Mechanical Characteristics of Alluvial Clayey Soil (반복하중,온도변화 및 초기조건이 충적점토의 구조변화와 역학적 특성에 미치는 영향)

  • 유능구;유영선;최중대;김기성
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.34 no.4
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    • pp.69-79
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    • 1992
  • To estimate soil behavior and structural characteristics under the conditions of cyclic loading, freezing & thawing and initial state, several testing was performed and obtained following results. 1.After repeated freezing and thawing processes, original soil structure was destroyed and changed to globular structure from honeycomb or tube in its structure types. Also above processes resulted increasing the soil compression strain while decreasing the failure stress in stress-strain relationship and reached the soil structure into the mode of brittle fracture. Under cyclic loading conditions, soil cluster which was originally dispersed structure colloided with each other, seperated, and finally the soil failed due to the effect of overcompaction. 2.Through the stabilization processes seperated by four steps, the structure of soil skeleton was changed to quite different globular type. The degree of compressibility of soil was decreased in the normally consolidated zone, while the strength against external load increased due to soil particle stabilization. 3.Soil stress-strain chracteristics were largely influenced by repeated up and down processes of temperature. The maximum deformation was obtained in the case of temperature between 0 10˚C by the reseon of particle cluster reformation. 4.Soil compressibility was largely influenced by the optimum moisture content. Under freezing process, swelling could be found and its magnitude was proportional to the density of soil. 5.Density of soil was decreased as increasing the number or repeated freezing and thawing processes and the largest decreasing rate was found at the first turning point from freezing to thawing cycle.

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A Study on Logarithmic Stress Singularities for V-notched Cracks in Isotropic Dissimilar Materials (등방성 이종재료 내의 V-노치 균열에 대한 대수 응력특이성에 관한 연구)

  • 김우진;김진광;조상봉
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1997.10a
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    • pp.747-750
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    • 1997
  • Using complex potentials and the concept of repeated roots for general solutions, logarithmic stress singularities and coefficient vectors for v-notched cracks in isotropic dissimilar materials are evaluated and demonstrated to have no influence on the logarithmic stress singularities.

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The application of forman equation for fatigue crack propagation in welding residual stress region (溶接殘留應力領域에서의 疲勞균열傳播에 대한 Forman式의 適用)

  • 김상철;이용복
    • Journal of Welding and Joining
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    • v.5 no.1
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    • pp.42-56
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    • 1987
  • Fatigue Fracture behaviors of the TIG-welded aluminum alloys, such as Al 2024-T4, A1 5050-0 and Al 7075-T7 were investigated when a crack propagated from tensile residual stress region and compressive residual stress region. The experimental values were compared with the values expected by the Forman equation. The experimental results are summarized as the following: (1) In case of fatigue crack propagation from residual stress region, the values predicted by Forman equation were Found to exactly corresponded to the experimental values. (2) When the stress intensityfactors affected by compressive residual stress, Kres, were greater than the stress intensity factors by minimum applied stresses. Kmin, the Forman equation was found to be improper to be applied directly, but the equation appeared to be proper, if the stress ratio was modified to zero. (3) The experimental results confirmed that residual stress was relaxed by repeated tensile loading and the relaxing trend was greater in case of compressive residual stress than that of tensile residual stress.

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Stress Intensity Factors and Possible Crack Propagation Mechanisms for a Crack Surface in a Polyethylene Tibia Component Subject to Rolling and Sliding Contact (구름마찰 접촉하중시 Polyethylene Tibia 표면균열의 응력확대계 수와 복합전파거동에 관한 연구)

  • Kim, Byung-Soo;Moon, Byung-Young
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.27 no.12
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    • pp.2019-2027
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    • 2003
  • Pitting wear is a dominant from of polyethylene surface damage in total knee replacements, and may originate from surface cracks that propagate under repeated tribological contact. In this study, stress intensity factors, K$\_$I/and $_{4}$, were calculated for a surface crack in a polyethylene-CoCr-bone system under the rolling and/or sliding contact pressures. Crack length and load location were considered in determination of probable crack propagation mechanisms and fracture modes. Positive K$\_$I/ values were obtained for shorter cracks in rolling contact and for all crack lengths when the sliding load was apart from the crack. $_{4}$ was the greatest when the load was directly adjacent to the crack (g/a=${\pm}$1). Sliding friction caused a substantial increase of both K$\_$I/$\^$max/ and $_{4}$$\^$max/. The effective Mode I stress intensity factors, K$\_$eff/, were the greatest at g/a=${\pm}$1, showing the significance of high shear stresses generated by loads adjacent to surface cracks. Such behavior of K$\_$eff/ suggests mechanisms for surface pitting by which surface cracks may propagate along their original plane under repeated rolling or sliding contact.

Measurement reliability of irreversible stress/strain limits in Sn-Cu double layer stabilized IBAD/RCE-DR processed GdBCO coated conductor tapes under uniaxial tension at 77 K

  • Bautista, Zhierwinjay;Diaz, Mark Angelo;Shin, Hyung-Seop;Lee, Jae-Hun
    • Progress in Superconductivity and Cryogenics
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    • v.20 no.4
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    • pp.36-40
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    • 2018
  • In this study, the electromechanical properties in Sn-Cu double layer stabilized GdBCO coated conductor (CC) tapes with and without external lamination under uniaxial tension were examined at 77 K and self-field. Their irreversible stress and strain limits were determined using a loading-unloading scheme based on different critical current ($I_c$) recovery criteria. The repeated tests were performed and statistical estimation was done to check the reproducibility depending on the criterion adopted in evaluating the electromechanical properties. From the results, it showed that the Sn-Cu double-layer stabilized CC tapes have the higher irreversible stress limit, but lower irreversible strain limit as compared to brass laminated ones. Through the repeated tests, it can be found that a small scattering of irreversible limits existed in both CC tape samples. Finally, similar strain sensitivity of $I_c$ in both CC tapes was obtained.