• 한국생산제조학회지
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• 제7권2호
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• pp.54-61
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• 1998

This paper examines the crack growth behavior of 7075-T651 aluminum alloy for small tensile overload under high-low block loading condition. The cantilever beam type specimen with a chevron notch is used in this study. The crack growth and closure are investigated by compliance method. The applied initial stress ratios are R=-0.5 R=0.0 and R=0.25 Crack length, effective stress intensity factor range, ratio of effective stress intensity factor range and crack growth rate etc, are inspected with fracture mechanics estimate.

• 한국가시화정보학회지
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• 제13권2호
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• pp.28-32
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• 2015

Blood flow simulations in an realistic carotid bifurcation model with considering wall compliance were carried out to investigate the effect of wall elasticity on the wall shear stress and wall solid stress. Canonical waveforms of flow rates and pressure in carotid arteries were imposed for boundary conditions. Compared to a rigid wall model, we found an increased recirculation region at the carotid bulb and an overall reduction of wall shear stress in a compliant model. Additionally, there was appreciable change of flow rate and pressure wave in longitudinal direction. Both solid and wall shear stress concentration occur at the bifurcation apex.

• 한국자동차공학회논문집
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• 제7권5호
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• pp.186-193
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• 1999

In this paper, a full vehicle model is developed to analyze toe and camber changes due to rack height variation and compliance. The AutoDyn7 program developed in G7 project is used for the computer simulation. Steady state cornering test was done to find the understeer gradient. Imposing a pulse steer input, Frequency Response Function(FRF) of yaw rate and lateral accelerations were evaluated. To verify the stability, the rhombus using four parameters is employed. Steer characteristics were evaluated by changing the rack height and the bushing lateral stiffiness. which installed between the low control arm and the chassis.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1996년도 가을 학술발표회 논문집
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• pp.101-107
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• 1996

In this study, the wedge splitting test (WST) specimens with various strength levels were tested to investigate the fatigue crack growth behavior of concrete. Selected test variables were concrete compressive strength with 2 levels (28 MPa, 60 MPa, 100 MPa) and maximum fatigue loading with 2 levels (75%, 85%). Fatigue testing was preceded by fracture energy test and the crack growth was measured by means of the compliance calibration method, 60 WST specimens were cast for the fatigue test, and 6 companion cylinders ($\phi$100${\times}$ 200 mm) for each batch. In fatigue test, the frequency of loading cycle was 1 Hz, and the minimum fatigue loading level was 5~10 % of ultimate monotonic loading. On the basis of the experimental results, a fracture mechanics-based empirical relationships for fatigue crack growth rate (da/dN-$\Delta$KI relationships) were presented. In addition, the effect of initial notch depth on the fracture energy and the validity of compliance calibration technique for the WST were shown.

• 대한의용생체공학회:의공학회지
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• 제20권5호
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• pp.593-599
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• 1999

수축절정기에 0.2mm, 0.4mm 두께의 소구경 인조혈관의 내경3.2mm의 동맥에 문합한 단단문합 주위의 유동과 구조해석을 동시에 수행하였다. 유동해석 결과 속도분포 및 벽단전률은 타 연구결과와 매우 유사하며 이론해와 매우 유사함을 보였다. 유동에 의해서 문합부 주위에 작용하는 응력은 문합부에 집중되며 이는 수십만 pa에 달했다. 또한 인조혈관과 동맥에 작용하는 원주방향의 응력을 이론해와 비교한 결과 서로 유사함을 보였으며 두께가 얇은 인조혈관을 사용하는 경우 문합부의 compliance mismatch 는 개선되나 반대로 응력은 더 많이 받음을 알 수 있었다. 본 연구를 통해서 유체에 의하여 혈관이 영향을 받는 심혈관계 현상을 연구하는데 있어서 이와 같은 유체-구조 상호작용을 고려하여 동시에 해결 하는 방법은 매우 유용할 것으로 생각된다.

• Journal of the Optical Society of Korea
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• 제12권4호
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• pp.355-358
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• 2008

In the current GPON market and standard, the line bit rate requirement is changing from 1.25 Gbps to 2.5 Gbps. We fabricate a 2.5 Gbps burst-mode receiver with commercially available blocks and optimize it with an APD bias control. A burst-mode measurement setup is made for the full compliance test with the GPON standard. The device meets the partially defined 2.5 Gbps specs in the current ITU G.984.2 standard, also, supports 1.25 Gbps specs for the coexistence issue in an access network. The full-compliant measurement values can be used as a guideline for fixing "for further study" specs in the current GPON standard at 2.5 Gbps.

• 한국정밀공학회지
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• 제14권4호
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• pp.136-144
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• 1997

The characteristics of fatigue crack growth subject to out-of-plane bending fatigue are studied in terms of crack opening behavior by using pre-cracked smooth specimens. Crack opening stress is measured by an elastic compliance method which may precisely and continuously provide many date using strain gages during experiment. The results of the short crack and the long crack arranged by crack closure concept show that the effective stress gange ratio of short crack is grester than that of long crack, and ano- malous growth behavior of short crack may be elucidated by the variation of crack opening stress. When the variation of fatigue crack growth rate is arranged versus effective stress intensity factor range. Iinear relation is held also for the short crack. It shows that growth behavior of short crack can be quantitatively represent- ed by the fracture mechanics parameter using effective stress intensity factor range.

• 콘크리트학회지
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• 제9권3호
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• pp.127-135
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• 1997

본 연구에서는 콘크리트의 피로균열 성장거동을 구명하기 위하여 쐐기쪼갬실험( WST)을 수행하였다. 연구의 주안점인 피로균열 성장거동의 주요영향인자는 콘크리트의 강도로서 28,60,118 MPa 등 3가지의 강도를 변수로 택하였다. 한편, 응력비를 6,13%의 2가지로 변화시켜 그 영향을 관찰하였다. 소정의 응력비을 주기 위하여 최고피로하중수준을 75~85%, 최저응력수준을 5~10%로 각각 유지하였다. 피로실험전에 균열개구변위( CMOD)컴플라이언스 보정 실험을 수행한 후, 그 결과인 균열길이와 컴플라이언스의 관계를 피로실험 중에 균열길이를 예측하는데에 이용하였다. 또한 CMOD컴플라이언스 보정법의 타당성을 검증하기 위하여 선형탄성 파괴역학( LEFM) 및 염색법에 의하여 예측된 균열길이와 비교하였다. 실험결과에 의하여 선형탄성 파괴역학에 근거한 피로균열 성장속도 모델(da/dN- K1 관계)을 제시하였고 콘크리트의 강도가 증가함에 따라 피로균열의 성장속도가 빨라지는 것으로 평가되었다. 또한 응력비가 피로균열 성장속도에 영향을 미치는 것으로 나타났는데 강도가 증가함에 따라 그 정도가 감소하는 경향을 보였다. LEFM 과 염색법 의하여 예측된 균열길이와 비교하여 본 결과 CMOD컴플라이언스 보정법이 쐐기쪼갬실험(WST)에 적용될 수 있음이 검증되었다.

• 대한간호학회지
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• 제30권3호
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• pp.560-570
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• 2000

This study is aimed at developing a cardiac rehabilitation program and enlightening the effects of the program on patient's health behavior compliance, cardiovascular functional capacity, and quality of life. Using a quasi-experimental approach the nonequivalent control group pretest - posttest design was accepted for this study. The subjects of this study consisted of 55 patients with ischemic heart disease at the Cardiac Center of 'G' Hospital located in Inchon from May 1, 1998 to April 30, 1999. The patients were divided into two groups: the experimental group, which participated in the cardiac program with 30 patients and 25 patients of a control group were not involved in the program. There were two phases in the cardiac rehabilitation program: the first phase was a team approach education. It focused on reducing the risk of ischemic heart problems. The second phase was individual training by using a home based exercise program, which was comprised of 8 weeks, three sessions per week, 40-60 minutes per session, and followed by consultation. Every session involved 20-40 minutes of aerobic exercise at 40-60% of heart rate reserve, 11∼13 RPE and 10 minutes of warm-up and 10 minutes of cool-down exercises. The experimental tools for the study were the health behavior compliance scale developed by Lee, Yoon-hee (1992), and quality of life scale developed by McGirr et al.(1990). RPPsubmax were measured by the treadmill. The collected data was processed by SPSS and analyzed by χ²test and t-test. The results of this study were as follows: 1. The health behavior compliance in experimental group was significantly increased (t=5.091, p=.000) when compared to the control group. 2. RPPsubmax also decreased significantly in the experimental group when compared to the control group(t=-2.109, p=.040). 3. The quality of life significantly improved in the experimental group (t=3.853, p=.000) as compared to the control group. As the above results of this study revealed, the effectiveness of the cardiac rehabilitation program of the study was confirmed. It increased the health behavior compliance for reducing the risk of further coronary events, enhanced the cardiovascular functional capacity, and eventually improved the patient's quality of life.

• 디지털융복합연구
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• 제10권11호
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• pp.541-550
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• 2012

본 연구의 목적은 유산소성운동과 반신욕 처치의 차이가 비만 중년남성의 혈액성분, 호흡순환기능 및 혈관탄성에 어떠한 영향을 미치는가를 규명하기 위한 목적으로 수행되었다. 본 연구의 대상자는 비만 중년남성 30명을 선정하여 유산소성운동집단(n=10), 반신욕 처치집단(n=10), 통제집단(n=10)으로 구분하여 3집단으로 구성하였다. 이들은 12주간 유산소성운동프로그램 및 반신욕 처치 전 후 각 혈액성분, 호흡순환기능 및 혈관탄성의 변화를 살펴보기 위하여 반복이 있는 이원변량분석(repeated 2-way ANOVA)을 실시하였으며, Scheffe 방법을 이용하여 사후분석을 실시하였으며 다음과 같은 결과를 얻었다. 첫째, 12주간 처치 후 유산소성운동 참여집단의 모든 혈액성분은 반신욕집단과 통제집단에 비해 유의하게 감소 및 증가하였으며, 반신욕집단은 Triglyceride, LDL-C, HDL-C에서 통제집단에 비해 유의한 차이를 나타내었다. 특히, HDL-C의 수준은 유산소성 운동집단과 반신욕 집단간에 유의한 차이를 보이지 않았다. 둘째, 12주간 처치 후 최대산소섭취량, 최대심박수, 최대환기량은 유산소성 운동집단이 반신욕과 통제집단에 비해 유의하게 증가하였다. 그러나 반신욕집단과 통제집단간에는 유의한 차이가 나타나지 않았다. 셋째, 혈관탄성은 유산소 운동집단이 반신욕집단과 통제집단에 비해 왼팔,오른팔 및 왼다리, 오른다리에서 유의하게 향상된 것으로 나타났으며, 반신욕집단 역시 통제집단보다 혈관탄성이 향상된 것으로 나타났다. 이상의 결과를 종합하여 볼 때 유산소성 운동과 반신욕 참여는 비만 중년 남성의 혈액성분 개선과 혈류순환 및 혈관기능의 개선에 효과적인 것으로 나타났다.