• 한국체육학회지인문사회과학편
• /
• 제55권2호
• /
• pp.603-615
• /
• 2016

본 연구는 건강한 중년여성 28명을 대상으로 강도별 유산소운동을 12주간 주 3회로 실시하여 혈압, 레닌-알도스테론계, 신경전달물질 및 인지기능, 작업기억의 변화와 처치 후 인지기능에 영향을 미치는 요인을 분석하고자 실시하였다. 모집된 대상자를 통제집단 9명, 중강도 유산소운동집단 10명(50%V02max), 고강도 유산소운동집단 9명(70%V02max)으로 구분하여 처치 전과 후 반복측정 분산분석과 다중회귀분석을 실시한 결과 다음과 같은 결과가 나타났다. 중강도 유산소운동은 레닌, BDNF, 인지기능과 작업기억을 증가시키고, 알도스테론, 안지오텐신II, 알도스테론-레닌 비율을 감소시켰다. 고강도 유산소운동은 BDNF, 인지기능, 작업기억을 증가시키고 수축기혈압을 감소시켰다. 또한 강도별 유산소운동 후 인지기능에 미치는 요인을 회귀분석한 결과 중강도 유산소운동은 이완기혈압, 레닌-알도스테론 비율의 감소와 작업기억, BDNF의 증가가 인지기능에 영향을 미쳤고, 고강도 유산소운동은 작업기억 BDNF, 세로토닌의 증가가 인지기능에 영향을 미쳤다. 따라서 중강도 이상의 유산소운동은 중년여성의 인지기능 및 작업기억을 향상시키는 것을 알 수 있었다. 또한 인지기능 향상에 영향을 미치는 대사적 요인으로 중강도 유산소운동은 레닌-알도스테론 조절과 작업기억이었고 고강도 유산소운동은 신경전달물질과 작업기억으로 나타났다.

• Journal of Mechanical Science and Technology
• /
• 제17권11호
• /
• pp.1659-1664
• /
• 2003

A cracked plate with a patch bonded on one side was treated with a crack-bridging model using weight function: assuming continuous distribution of springs acting between th crack surfaces, the stress intensity factor of the patched crack was numerically obtained. Especially in the case of a patched crack subjected to residual non-uniform stress, the stress intensity factor was easily with the corresponding approximate weight function. This paper presented the stress intensity factors for a crack partially patched within a finite plate or a patched crack initiated from a notch.

• Journal of the Korean Data and Information Science Society
• /
• 제21권3호
• /
• pp.555-560
• /
• 2010

One-dimensional approach to two-dimensional warranty data involves modeling us- age as a function of time. Iskandar (1993) suggests a simple linear model for usage. However, simple linear form of intensity function is of limited value to model the situa-tion where the intensity varies over time. In this study Weibull intensity is considered where the scale parameter is expressed in terms of different models. We will nd out how each parameter in the model a ects the warranty cost and which model gives a bigger number of failures within the two-dimensional warranty region.

• 국제물리치료학회지
• /
• 제12권1호
• /
• pp.2295-2301
• /
• 2021

Background: Physical therapy applied to stroke patients is recognized as a treatment that promotes function recovery, and it is a widely known fact that constant exercise should be performed. However, there are insufficient studies on exercise intensity and exercise time that can minimize side effects and maximize function recovery for exercise therapy. Objectives: To determine the effect of exercise variables on CPK generation during aerobic exercise in stroke patients and to discover how to use appropriate exercise intensity and time when conducting an exercise for function recovery in stroke patients. Design: Quasi-experimental research. Methods: This study classified subjects into three groups (low-intensity exercise group: LIE, moderate-intensity exercise group: MIE and high-intensity exercise group: HIE) according to exercise intensity, and was further classified into two groups (10-minute exercise group: 10MG and 20-minute exercise group: 20MG) according to exercise time variables within each exercise intensity group. After, the change in CPK according to exercise intensity and time was confirmed through hematological analysis. Results: In LIE and MIE, the CPK blood concentrations before and after exercise were increased in 10MG and 20MG, which was not statistically significant (P>.05). In HIE, the CPK blood concentrations before and after exercise were increased in 10MG, and it was statistically significant (P<.05). In HIE, the CPK blood concentrations before and after exercise were increased in 20MG, and it was statistically significant (P<.01). In 10MG and 20MG, the CPK blood concentrations before and after exercises were increased in all intensity group, and there was a statistically significant difference only in HIE. Conclusion: From the results of this study, considering CPK, it will be helpful to recover and improve function if the exercise intensity setting is applied in the type of moderate intensity exercise during physical therapy interventions in stroke patients.

• 대한기계학회논문집A
• /
• 제25권10호
• /
• pp.1671-1677
• /
• 2001

Cracks at mechanical fastener holes usually nucleate as elliptical comer cracks at the faying surface of the mechanical joints and grow as elliptical arc through cracks. The weight function method for elliptical arc through cracks at mechanical fastener holes has been developed and verified in the part I of this study. In part H, applying the weight function method, the effects of the amount of clearance on the mixed-mode stress intensity (actors are investigated and the change of crack shape is predicted from the analysis for various crack shapes. The stress intensity factors leer inclined crack are analyzed and critical angle at which mode I stress intensity factor becomes maximum is determined.

• 대한기계학회논문집
• /
• 제19권2호
• /
• pp.463-474
• /
• 1995

Modified Vainshtok weight function method is developed. The thermal shock stress intensity factors for elliptical surface cracks existed in the thin and thick walled cylinders are determined. The present results are compared with previous solutions and shown to be good agreement with them.

• 대한기계학회논문집A
• /
• 제25권10호
• /
• pp.1659-1670
• /
• 2001

It has been reported that cracks at mechanical fastener holes usually nucleate as elliptical corner cracks at the faying surface of the mechanical joints and grow as elliptical arc through cracks after penetrating the opposite surface. The weight function method is an efficient technique to calculate the stress intensity factors fur elliptical cracks using uncracked stress field. In this study the weight function method for three dimensional mixed-mode problem applied to elliptical comer cracks Is modified for elliptical arc through cracks and the stress intensity factors at two surface points of elliptical arc through cracks at mechanical fastener holes are analyzed by the weight function method. This study consists of two parts and in part I , the weight function method for elliptical arc through cracks is developed and verified.

• 대한기계학회논문집A
• /
• 제24권9호
• /
• pp.2344-2352
• /
• 2000

Mechanical joints such as bolted or riveted joints are widely used in mechanical components. The reliable determination of the stress intensity factors for cracks in bolted joints is needed to evaluate the safety and fatigue life of them. The weight function method is an efficient technique to calculate the stress intensity factors for various loading conditions because only the stress analysis of an uncracked model is required. In this paper the mixed-mode stress intensity factors for cracks in bolted joints are obtained by weight function method, in which the coefficients of weight function are determined by finite element analyses for reference loadings. Critical inclined angle that mode I stress intensity factor becomes maximum is determined and the effects of crack length and the magnitude of clearance on critical inclined angle are investigated.

• 한국산업융합학회 논문집
• /
• 제13권1호
• /
• pp.23-30
• /
• 2010

This paper presents a histogram equalization based on the nonlinear transformation function for enhancing the quality of medical images. The nonlinear transformation function is applied to adaptively equalize the brightness of the image according to its intensity level frequency. The logistic function is used as a nonlinear transformation function, which is calculated by only using the intensity level with maximum frequency and the maximum intensity level in an histogram, and the total number of pixels. The proposed method has been applied for equalizing 8 medical images with a different resolution and histogram distribution. The experimental results show that the proposed method has the superior enhancement performances compared with the conventional histogram equalization. And the proposed histogram equalization can be used in various multimedia systems in real-time.

• 대한기계학회논문집A
• /
• 제22권4호
• /
• pp.953-959
• /
• 1998

To investigate accuracy of intensity method for measurement of the fiber orientation distribution, fiber orientation function is calculated by drawing simulation figures for the fiber orientation as varying fiber aspect ratio, fiber area ratio, and fiber orientation state, respectively. The values of fiber orientation function measured by intensity method are compared with the calculated values of fiber orientation function. The results show that measurement accuracy of the fiber orientation angle distribution by intensity method is affected by the fiber aspect ratio when the total length of oriented fiber is same. The average gradient of fiber orientation function is 0.94 for 1000mm of the total fiber length and is 0.93 for 2000 mm when the fiber aspect ratio is over 50. Measurement accuracy by intensity method is about 94% and the reliable data can be obtained by intensity method.