• 한국지반공학회:학술대회논문집
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• 한국지반공학회 1999년도 봄 학술발표회 논문집
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• pp.471-477
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• 1999

A new stress, load and displacement controlled direct shear apparatus has recently been developed at the Hyundai Institute of Construction Technology This direct shear apparatus is capable of testing of rock joint under constant normal stiffness, constant normal stress or constant normal load boundary conditions. This paper describes this direct shear apparatus and illustrates results of shear tests at constant normal stress condition, constant normal load condition and constant normal stiffness condition with dental stones which have a same joint roughness and unconfined compressive strength.

• 한국해양공학회지
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• 제14권2호
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• pp.99-105
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• 2000

This paper describes the effect of specimen size on fatigue crack growth rate for the offshore structural high-tensile-strength steel BS4360 and machine structural steel SM45C. The purpose of the present study is to investigate the effect of stress ratio aspect ratio specimen width and specimen thickness of the fatigue crack growth behavior. Compact tension specimens with a LT orientation for BS4360 and SM45C steels were used, All testing was done at constant stress intensity factor range controlled fatigue crack growth condition. The investigation demonstrates that the fatigue crack growth rate is increased with increasing stress ratio and specimen thickness and is decreased with increasing specimen width. The fatigue crack growth rate is unaffected by aspect ratio until a/W=0.50 but is increased by increasing spect ratio from a/W=0.55.

• 셀메드
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• 제5권1호
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• pp.5.1-5.5
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• 2015

In this first double-blind-placebo-controlled investigation of the Aeon Patch, electrocardiographic data were acquired from 50 well-hydrated volunteers [21 females and 29 males, age: 19-79, weight: 117-334 lbs, height: 5'-6',3"], under 3 different conditions for a total duration of 15 min (5 min/condition). Condition1: Control (C) - while wearing no Patch, Condition 2: Placebo (P) or Active (A) - after wearing either the Placebo or the Aeon Patch for 20 min, and Condition 3: Active (A) or Placebo (P) - after wearing either the Aeon or the Placebo Patch for 20 min. There was a washout period of 15 min between Conditions 2 and 3. All involved in the investigation were blind to the (A) and (P) Patches as they looked exactly the same and were assigned in a random fashion. The hypothesis to be tested was: Wearing the Aeon Patch for 20 min reduces stress. Data were first quality assured and those subjects who showed a parasympathetic response after wearing the Patch within 20 min were identified as early responders. Thirty subjects (60%) achieved a relaxed state after wearing the Aeon Patch as early as 20 min. Statistical analysis (one-sample inference) was used to compare the spectral features of the responders. The normalized LF/HF decreased significantly ($24%{\pm}9%$ after 20 min) in condition (A) compared to condition (P) with a p-value < 0.047 (n = 30) in responders. Therefore, the hypothesis that wearing the Aeon Patch for 20 min reduces stress was accepted as true.

• 소성∙가공
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• 제6권2호
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• pp.102-109
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• 1997

The multistage deformation and stress relaxation were carried out to investigate the strain induced precipitation by torsion tests in the range of 1000~80$0^{\circ}C$, 0.05~5/sec for V-microalloyed steel. The starting temperature and time for the initiation of precipitation were determined by stress relaxation tests. The distribution of precipitates increased, as the strain rate increased and the mean size of precipitates was found to be about 10~30nm. The precipitation starting time$(P_s)$ decreased with increasing strain rate and the amount of pre-strain. The effect of deformation conditions on the no-recrystallization temperature$(T_nr)$ was also determined in the multistage deformation. $T_nr$ Tnr decreased with increasing the strain and strain rate. In the controlled rolling simulation, grain refinement and precipitation hardening effects could be achieved by the alternative large pass strain at the latter half pass stage under the condition of low temperature and high strain rate.

• 기본간호학회지
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• 제12권3호
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• pp.389-394
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• 2005

Purpose: This study was done to examine the relationship between life stress and depression, and the effect of social support of 100 Koreans living in the Phillippines. Theoretically social support is considered to mediate the relationship between lift stress and depression. Method: Data were collected from April 1 to May 30, 2002 and analysed using SAS. The first, two hypotheses were tested using Gamma, a measure of association for ordinal variables. Partial gamma was used to test the third hypothesis. Patterns of elaboration described by Babbie(1986) were selected to interpret the relationship of the three variables in the analysis. Results: 1) There was a positive relationship between life stress and depression(Gamma=.45, p=.017), and a inverse relationship between social support and depression(Gamma=-.561, p=.002). Thus the first, two hypotheses were supported. 2) When social support was controlled, the relationship between life stress and depression increased under the condition of low social support but with high social support, the relationship decreased. Conclusion: It can be interpreted that life stress is positively related to depression under the condition of low social support, however this relationship may be reversed with high social support.

• 기본간호학회지
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• 제8권2호
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• pp.199-209
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• 2001

The purpose of this study was to examine the relationship between life stress and depression, and the effect of social support in postpartal $4{\sim}6$ week women. Theoretically social support is thought to mediate the relationship between life stress and depression. Data were collected from June 1 to July 30, 1999. The data were analysed by use of SPSS. Two hypotheses were tested using Gamma, a measure of association for ordinal variables. Partial gamma was used to test the third hypothesis. Patterns of elaboration described by Babbie(1986) were selected to interpret the relationship of the three variables in the analyses. The results of this study are summarized as follows ; There was a positive relationship between life stress and depression (Gamma=.45, P=.017), and an inverse relationship between social support and depression (Gamma=-.49, P=.009). Thus the first, two hypotheses were supported. 2. When social support was controlled, the relationship between life stress and depression increased under the condition of low social support, but with high social support, the relationship decreased. It can be interpreted that life stresses are positively related to depression under the condition of low social support, however this relationship cannot be expected with high social support.

• 한국기계가공학회지
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• 제6권1호
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• pp.50-56
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• 2007

Exhaust manifold is generally subjected to thermal cycle loadings ; at hot condition, large compressive plastic deformations are generated, and at cold condition, tensile stresses are remained in highly deformed critical zones. These phenomena originate from the fact that thermal expansions of the runners are restricted by inlet flange clamped to the cylinder head, because the former is less stiff than the latter and, the temperature of the inlet flange is lower than that of the runners. Since the failure of an exhaust manifold is mainly caused by geometric constraints between the cylinder head and the manifold, the thermal stress can be controlled by geometric factors. The generic geometric factors include the inter distance (2R), the distance from the head to the outlet (L), the tube diameter(d) and the tube thickness (t). This criteria based on elastic analysis up to onset of yield apparently indicate that the pre-stress also reduces the factor; however, high temperature relaxation may reduce this effect at later operation stage.

• 대한간호학회지
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• 제19권1호
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• pp.99-107
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• 1989

This study explored differences in how medical and surgical patients compare on the degree of hospital stress and their subjective physical status. Subjects were 343 medical and surgical patients in five university hospitals in Seoul and Taegu. They responded to the Hospital Stress Rating Scale and a self-report on physical status. The controlled variables were age, education, number of previous hospitalizations and seriousness of the illness. Medical and surgical patient differences on nine factors of the hospital stres scale and nine areas of physical conditions were reported as follows edplored : 1. 1) There was not a statistically significant difference at the .05 level in the total mean score for hospital stress between medical patients and surgical patients. 2) The mean score of the factor lack of information (M＝2.308) for medical patients was higher than the mean score (M＝2.064) of the surgical patients. 3) The mean scores of the factor of discomfort (M＝2.130), loss of independence (M＝1.889) for surgical patients were higher than for medical patients. 2. 1) There was a statistically significant difference at the .05 level in the total mean score for physical status between medical patients and surgical patients. 2) The mean scores were lower in subjective physical status for surgical patients(S) than for medical patients (M) ; stomach condition (S : M＝2.8433, M : M＝3.0-000), self-assistance(S : M＝3.0373, M : M＝3.4498), movement (S : M＝2.6716, M : M＝3.2392), interest in your surroundings (S : M＝3.0522, M : M＝3.2632). 3. Patients scoring high on the subjective physical status such as sleep, appetite, stomach condition bowel condition and urination states had higher scores in hospital stress than with patients scoring low on those subjective Physical status. The results suggest that subjective physical status might be on expression of hospital stress. Also patients with high scores in subjective physical statas might be predicted have a high level of stress on admission. And surgical patients had a higher level of hospital stress than medical patients.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2003년도 추계학술대회 논문집(II)
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• pp.466-471
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• 2003

The characteristics of a rock joint which influence the stability of rock mass structures, such as the cut slopes and the tunnels, are largely controlled by the conditions of the rock joint as well as its boundary conditions. Boundary conditions can be represented by assuming that the deformability(or stiffness) of the rock mass surrounding the joints is modelled by a spring with stiffness. A new direct shear apparatus is developed in this study, which adapts a servo control system using PID algorithm. This apparatus can be used to investigate the various aspects of shear characteristics of the rock joints at conditions of constant normal stress and constant normal stiffness and so on. It is possible that the behavior under the constant normal stiffness condition can be predicted by the normalized graphic method with results obtained from the tests in the constant normal stress condition.

• Journal of Advanced Marine Engineering and Technology
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• 제22권6호
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• pp.763-770
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• 1998

This paper deals with evaluation of bending fatigue strength in SCM415 carburized spur gears. The constant stress amplitude fatigue test is performed by using an electrohydraulic servo-controlled pulsating tester. The S-N curves are obtained and the enhanvement of fatigue strength due to carburized treatment is clarified. In this study the improvement of fatigue strength is assumed to be caused by an increase of both hardness and residual stress and experimental formula has been proposed for the estimation of bending fatigue strength of carburized gears. The effect of surface conditions on the fatigue strength is evaluated quantitatively and it is close to the relative surface condition factor used in the ISO strength rating formula.