• Structural Engineering and Mechanics
• /
• 제54권3호
• /
• pp.393-417
• /
• 2015

In this paper an 8-node quadrilateral assumed stress hybrid Mindlin plate element with $39{\beta}$ is presented. The formulation is based on complementary energy principle. The proposed element is free of shear locking and is capable of passing all the patch tests, especially the non-zero constant shear enhanced patch test. To accomplish this purpose, special attention is devoted to selecting boundary displacement interpolation and stress approximation in domain. The arbitrary order Timoshenko beam function is successfully used to derive the boundary displacement interpolation. According to the equilibrium equations, an appropriate stress approximation is rationally derived. Particularly, in order to improve element's accuracy, the assumed stress field is derived by employing $39{\beta}$ rather than conventional $21{\beta}$. The resulting element can be adopted to analyze both moderately thick and thin plates, and the convergence for the very thin case can be ensured theoretically. Excellent element performance is demonstrated by a wide of experimental evaluations.

• Journal of Veterinary Science
• /
• 제24권2호
• /
• pp.33.1-33.7
• /
• 2023

Background: Laminitis is a complex and debilitating disease of horses. Numerous predisposing factors contribute to laminitis development, however the exact pathogenesis remains undetermined. Serum T4, cortisol, and histamine are components of the innate stress response and could play a causative or contributory role. Stress hormone concentrations in laminitis are largely unknown. Objective: To evaluate parameters associated with stress response in horses with laminitis, and compare these to healthy horses and horses with gastrointestinal (GI) disease. Methods: Thirty-eight adult horses presenting for non-medical conditions, GI abnormalities, or clinical laminitis were prospectively enrolled. Horses were assigned to the appropriate disease group (healthy, GI disease, and laminitis) and had blood drawn on presentation to the hospital. Samples were analyzed for plasma endogenous adrenocorticotrophic hormone (eACTH), serum cortisol, serum thyroid hormone, and plasma histamine. Results: Stress hormone concentrations were significantly different between horses in the laminitis and GI disease groups. Plasma histamine levels were highest in horses with laminitis, compared with GI disease and controls. Both horses with laminitis and GI disease had increased plasma eACTH when compared to healthy horses. Horses with GI disease had higher serum cortisol concentrations than horses with laminitis or controls. Serum T4 was lower in horses with GI disease than in horses with laminitis and controls. Conclusions: Horses with laminitis had relative increases in both plasma histamine and eACTH concentrations. Serum T4 and cortisol concentrations of horses with laminitis did not differ significantly when compared to healthy horses. The role of stress hormones in equine disease warrants further investigation.

• 한국식물병리학회:학술대회논문집
• /
• 한국식물병리학회 2002년도 총회 및 추계학술발표회
• /
• pp.85.2-86
• /
• 2002

• 한국간호교육학회지
• /
• 제7권1호
• /
• pp.7-21
• /
• 2001

The purpose of this study was identify the level of stress, anger and anger expression in the clinical setting and identify the relation ships between anger and stress of nursing students in the clinical setting. A convenient sample of 213 junior college of nursing students was used for the study. The data were analyzed by descriptive statistics and Pearson Correlation Coefficients. The results of this study were summarized as follows : 1. The average stress score in the clinical setting of subjects was 3.87. The higher level of stress in the clinical setting was 4.10 in domain of nurses, 4.10 in domain of human relationships, 4.07 in domain of report and 3.89 in domain of relationship between nursing theory and practice. 2. The average state-anger score of subjects was 1.54. 3. The average anger-out score of anger expression mode was 1.66 and 2.36 in anger-in. 4. The state-anger was found significantly related to stress of nursing students in the clinical setting (r=0.256 p<0.001). In the relationship between state- anger and stress in the clinical setting, environment, patient relationship, between nursing theory and practice, nurses, report, orientation were significantly positive correlation . 5. The anger-out of anger expression mode was not found significantly related to stress of nursing students in the clinical setting. 6. The anger-in of anger expression mode was found significantly related to stress of nursing students in the clinical setting (r=0.205 p<0.01). In the relationship between anger-in of anger expression mode and stress in the clinical setting, environment, patient, nurses, human relationships, conference were significantly positive correlation.

• 대한간호학회지
• /
• 제27권4호
• /
• pp.912-922
• /
• 1997

The purpose of this study was to examine the effect of supportive nursing on stress reaction of breast cancer patients undergoing chemotherapy. The nonequivalent control group pre-test/post-test design was used for this experimental study. The subjects were 32 patients who were receiving chemotherapy after mastectomies at K hospital in Taegu from June, 1994 to June 1995. Among 32 subjects, 16 were placed in the experimental group and 16 in the control group. The experimental and control groups were tested for general characteristics, trait anxiety, health locus of control, family support, state anxiety, hopelessness, physical stress, and anxiety behavior. Collected data was analized by means of a chisquare test and a t-test for the comparative analysis of the general characteristics and homogeneity of subjects. ANOVA, and MANOVA were used for testing the hypothesis. Reliability of the tools were analyzed using the Pearson Correlation coefficient. The results of this study were as follows : 1. The hypothesis : The stress reaction of the experimental group which took supportive nursing was lower than the stress reaction of the control group : this was supported statistically. The main variable influenced in stress reaction was hopelessness. Supportive nursing for breast cancer patients, who are receiving chemotherapy, was especially effective in the reduction of hopelessness compared to state anxiety, physical stress, and anxiety behavior. 2. An analysis of the difference on stress reaction, according to the frequency of supportive nursing between the control and experimental group, showed the level of hopelessness of the experimental group was lower than the control group after four supportive meeting sessions. But there was no statistical difference in state anxiety, physical stress, and anxiety behavior. In conclusion, this study supported utilization of supportive care as well as demonstrating the effectiveness of the System-Developmental Stress Model developed by Chrisman and Riehl-Sisca.

• 한국지반공학회논문집
• /
• 제15권4호
• /
• pp.3-17
• /
• 1999

대응력반전시 모래의 거동을 연구하기 위하여 여러 가지 응력경로에 따른 비틀림전단시험이 수행되었다. 응력경로는 토르크의 작용방향에 따라 시계방향과 반시계방향으로 구분할 수 있으며 대응력반전을 포함하는 응력경로에 대한 소성변형률증분의 방향이 응력상태 및 응력증분의 방향과 비교된다. 이들 시험 결과로부터, St, Venant의 원리를 이용한 등방경화이론은 최초재하와 파괴점 부근에서 소성변형률증분의 방향이 응력의 방향과 일치하는 좋은 결과를 나타내었으나 응력반전에 의한 감하과 재재하 부분에서는 차이가 있는 것으로 나타났다.

• 대한기계학회:학술대회논문집
• /
• 대한기계학회 2003년도 춘계학술대회
• /
• pp.25-30
• /
• 2003

The total relaxed stress in annealing and the thermal strain/stress were obtained from the identification of the residual stress-free state using electronic speckle pattern interferometry (ESPI). The residual stress fields in case of both single and film/substrate systems were modeled using the thermo-elastic theory and the relationship between relaxed stresses and displacements. We mapped the surface residual stress fields on the indented bulk Cu and the 0.5 ${\mu}m$ Au film by ESPI. In indented Cu, the normal and shear residual stress are distributed over -1.7 GPa to 700 MPa and -800 GPa to 600 MPa respectively around the indented point and in deposited Au film on Si wafer, the tensile residual stress is uniformly distributed on the Au film from 500 MPa to 800 MPa. Also we measured the residual stress by the x-ray diffractometer (XRD) for the verification of above residual stress results by ESPI.

• 대한기계학회논문집
• /
• 제16권9호
• /
• pp.1700-1710
• /
• 1992

본 연구에서는 경계요소법에 의해 천이상태 열전도문제를 해석하는 프로그램 과 Sladek등이 제안한 열탄성 경계적분방정식을 기초로 하여 열탄성문제를 해석하는 프로그램을 개발하여, 유한체 내에 존재하는 Griffith 균열에 대해 정상 및 천이상태 에서 계산한 열응력세기계수와 유한체 내에 존재하는 대칭 입술형 커스프균열(symme- tric lip cusp crack)에 대해 정상상태에서 열응력세기계수를 계산한다. 그 결과를 기존의 해와 비교하여 프로그램의 타당성을 입증한다. 그후 대칭 입술형 커스프균열 에 대한 천이상태에서의 열응력세기계수를 계산하고자 한다.

• 한국구조물진단유지관리공학회 논문집
• /
• 제12권1호
• /
• pp.158-166
• /
• 2008

프리스트레스하중이 작용되는 강합성교인 PSSC 교량에서 프리스트레스의 효과와 단면의 변형에 따른 텐돈의 변형의 영향을 밝히기 위해 사하중 및 활하중이 작용될 때 합성전 후에 발생하는 부재내의 변형도 및 응력변화와 허용응력 한계상태, 항복응력 한계상태 및 강도한계상태의 단면력과 부재내의 변형도 및 응력변화를 구한다. 또한 거더의 처짐 및 응력과 휨강도를 변수로 하는 한계상태들을 가정하고 이에 대한 신뢰도 분석을 수행한다. 허용응력에 맞추어 설계한 예제 단면의 응력에 대한 신뢰도 지수가 0 부근임에 비하여, 처짐 및 휨강도에 대한 신뢰도 지수는 높은 값을 주고 있어서 도로교설계기준의 허용응력에 대하여 설계한 PSSC 거더는 처짐 및 휨강도에 대하여 높은 신뢰도를 얻을 수 있음을 알 수 있다.

• 한국지반공학회논문집
• /
• 제26권7호
• /
• pp.7-16
• /
• 2010

응력이력은 사질토 지반의 잔류 수평응력을 증가시켜 현장시험의 관입저항을 증가시킨다. 본 연구에서는 챔버에 조성된 정규 및 과압밀 시료에 대한 콘관입시험과 딜라토미터 시험을 수행하고 응력이력이 시험결과와 측정값의 상관관계에 미치는 영향을 분석하였다. 시험결과, 평균 유효응력으로 정규화된 콘선단저항은 상대밀도 및 상태정수와 높은 상관성을 보였다. 딜라토미터의 수평응력지수($K_D$)는 콘선단저항($q_c$) 뿐만 아니라, 딜라토미터 계수($E_D$) 보다도 응력이력 영향을 효과적으로 반영하였다. 수평응력지수에 반영된 응력이력의 영향을 정지토압계수인 $K_0$로 보정한 $K_D/K_0$는 상대밀도 뿐만 아니라, 상태정수, 평균 유효응력으로 정규화된 콘선단저항과 응력이력에 관계없는 높은 상관성을 보였다. 또한 평균 유효응력으로 정규화된 딜라토미터 계수($E_D/{\sigma}_m'$)와 상태정수의 관계도 응력이력에 관계없이 유일한 식으로 표현되었다.