• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 2001년도 춘계학술발표대회 개요집
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• pp.220-223
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• 2001

In this study, CT specimens were prepared hem ASTM SA516 which was used for pressure vessel plates for room and low temperature service. And we got the following characteristics from fatigue crack growth test carried out in the environment of room and low temperature at $25^{\circ}C$, -3$0^{\circ}C$, -6$0^{\circ}C$, -8$0^{\circ}C$, -l$0^{\circ}C$ and -l2$0^{\circ}C$ and in the range of stress ratio of 0.1, 0.3 by means of opening mode displacement. At the constant stress ratio, the threshold stress intensity factor range ΔK$_{th}$ in the early stage of fatigue crack growth ( Region I ) and stress intensity factor range ΔK in the stable of fatigue crack growth ( Region II) was increased in proportion to descend temperature. It assumed that the fatigue resistance characteristics and fracture strength at low temperature is considerable higher than that of room temperature in the early stage and stable of fatigue crack growth region. The straight line slope relation of logarithm da/dN - ΔK in Region II, that is, the fatigue crack growth exponent m increased with descending temperature at the constant stress ratio. It assumed that the fatigue crack growth rate da/dN is rapid in proportion to descend temperature in Region H and the cryogenic-brittleness greatly affect a material with decreasing temperature.e.greatly affect a material with decreasing temperature.

• 대한간호학회지
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• 제31권4호
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• pp.681-691
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• 2001

Purpose: The exercise status in patients with rheumatoid arthritis, associations between exercise behavior and personal factors, and associations between exercise behavior and exercise-specific cognitions and their effects were assessed. Method: Four hundred thirty nine outpatients with rheumatoid arthritis were studied. The exercise status was measured by a single item. The intensity was multiplied by the frequency and duration of each exercise. The product of these intensity values for all exercises was defined as exercise behavior. Based on the Pender's revised health promotion model, exercise benefit, barrier, self-efficacy, enjoyment and social support were chosen as exercise specific cognitions and affect variables. Path analysis was used to identify the predictors of exercise behavior. Results: Compared to the duration before being diagnosed, the number of subjects who exercised regularly increased after being diagnosed. However over half of the subjects refrain from any sort of exercise and the type of exercise is very limited. Among the variables, exercise barrier, self-efficacy, and social support were found to be significant predictors of exercise behavior, and only previous exercise experience was found to be significant predictors of all behavior specific cognitions and affect variables. Conclusion: These findings suggest that studies should explore exercise behaviors and strategies to emphasize the cognitive-motivational messages to promote exercise behaviors.

• 벤처창업연구
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• 제16권4호
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• pp.101-113
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• 2021

이 연구는 기업벤처캐피탈에 대한 거시적경제, 산업구조적 관점에서 기업벤처케피탈 투자에 영향을 미치는 요인들에 대해 탐색한다. 기업벤처캐피탈 투자에 관한 기존 연구들이 모기업의 사업 다각화, 신규 사업 진출을 위한 기업벤처링(Corporate Venturing) 등 모기업과의 관련성을 중심으로 기업벤처캐피탈의 정체성과 투자목적에 대해 논의해온 것과 달리, 본 연구는 변화하는 거시경제적, 산업구조적 환경적 요인에 영향을 받고 이에 대응하는 독립적, 재무적 투자자로서의 기업벤처캐피탈의 정체성에 주목하여, 기업벤처캐피탈 투자에 미치는 영향을 분석한다. 이를 위해 구체적으로 산업 호황, 외생적 위기, 경제 성장, 산업 내 경쟁 강도 등과 같은 거시적 요인들이 기업벤처캐피탈 투자에 미치는 영향에 대해 1996년부터 2017년까지 84개 미국 기업벤처캐피탈의 2,306건의 투자데이터를 기반으로 실증분석하였다. 분석결과 일반적인 독립벤처캐피탈과 마찬가지로 산업이 호황이고, 경제가 성장할 때는 기업벤처캐피탈도 투자를 늘리고, 외생적 위기가 발생하거나, 기업벤처캐피탈들 간 경쟁 강도가 강할수록 투자가 줄어들 것이라는 가설이 모두 지지되었다. 주로 모기업과의 관계, 피투자회사와 모기업 사업의 관련성 등을 중심으로 기업벤처캐피탈 투자에 대해 논의했던 선행 연구들과 달리, 기업벤처캐피탈의 재무적 투자자로서의 정체성과 기업벤처캐피탈 투자에 미치는 거시경제적, 산업구조적 요인들의 영향에 대해 환기함으로써 기업벤처캐피탈 투자에 대한 논의의 폭을 확장하고, 기업벤처캐피탈 투자의사결정자들에게 거시경제적, 산업구조적 요인들에 대한 대응을 시사한다는 점에서 의의가 있다.

• Geomechanics and Engineering
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• 제22권2호
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• pp.187-196
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• 2020

The changeable stress environment directly affect the propagation law of a stress wave. Stress wave propagation tests in sandstone with different axial stresses were carried using a modified split Hopkinson Pressure bar (SHPB) assuming the sandstone has a uniform pore distribution. Then the waveform and stress wave energy dissipation were analyzed. The results show that the stress wave exhibits the double peak phenomenon. With increasing axial stress, the intensity difference decreases exponentially and experiences first a dramatic decrease and then gentle development. The demarcation stress is σ/σ_c=30%, indicating that the closer to the incident end, the faster the intensity difference attenuates. Under the same axial stress, the intensity difference decreases linearly with propagation distance and its attenuation intensity factor displays a quadratic function with axial stress. With increasing propagation distance, the time difference decays linearly and its delay coefficient reflects the damage degree. The stress wave energy attenuates exponentially with propagation distance, and the relations between attenuation rate, attenuation coefficient and axial stress can be represented by the quadratic function.

• 한국생산제조학회지
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• 제24권5호
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• pp.481-488
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• 2015

It is difficult to see a therapeutic effect from cardiovascular disease treatment methods in the case of a hardened chronic total occlusion (CTO), owing to the calcification of the deposition materials. However, lesion cells, such as CTOs, can be selectively necrotized without affecting the normal tissue using high-intensity ultrasound focused on one point. In this study, a phantom CTO was necrotized by a high-intensity focused ultrasound (HIFU) energy system, and the acoustic characteristics in the focal region were analyzed. An experimental HIFU device was constructed to discover the appropriate conditions for the necrosis of a phantom CTO. The transfer characteristics of the ultrasound changed in the focal region by the density difference of the phantom CTO. These changes were acoustically analyzed to choose the available frequency band for each density. On-off temperature control in the focal region was applied to prevent rapid temperature rises, which would otherwise affect normal tissue.

• Wind and Structures
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• 제22권2호
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• pp.185-209
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• 2016

Across-wind aerodynamic damping ratios are identified from the wind-induced acceleration responses of 15 aeroelastic models of rectangular super-high-rise buildings in various simulated wind conditions by using the random decrement technique. The influences of amplitude-dependent structural damping ratio and natural frequency on the estimation of the aerodynamic damping ratio are discussed and the identifying method for aerodynamic damping is improved at first. Based on these works, effects of turbulence intensity $I_u$, aspect ratio H/B, and side ratio B/D on the across-wind aerodynamic damping ratio are investigated. The results indicate that turbulence intensity and side ratio are the most important factors that affect across-wind aerodynamic damping ratio, whereas aspect ratio indirectly affects the aerodynamic damping ratio by changing the response amplitude. Furthermore, empirical aerodynamic damping functions are proposed to estimate aerodynamic damping ratios at low and high reduced speeds for rectangular super-high-rise buildings with an aspect ratio in the range of 5 to 10, a side ratio of 1/3 to 3, and turbulence intensity varying from 1.7% to 25%.

• ALGAE
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• 제28권4호
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• pp.355-363
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• 2013

The coralline alga, Corallina officinalis, is a widely distributed intertidal species in temperate coastal regions. It is usually exposed to high fluctuations of light intensity, light quality, temperature, and desiccation, all of which affect the temporal and spatial distribution as well as the morphology and the metabolism of this alga. In laboratory experiments we examined the effects of different light intensities (50, 100, and 200 ${\mu}mol$ photons $m^{-2}s^{-1}$) on photosynthesis, calcification, photosynthetic pigment contents (chlorophyll a and carotenoids), and growth rate of C. officinalis to clarify its photoacclimation strategies. Net photosynthesis, calcification and dissolution rates based on weight were not sensitive to irradiance. Although, photosynthesis and calcification did not clearly respond to light intensity, photosynthetic pigment contents were significantly lower at higher light intensities. In addition, higher irradiances induced significant enhancement of gross photosynthesis based on chlorophyll a. As a result, the specific growth rate was significantly stimulated by high light intensity. Our results suggest that photoacclimation of C. officinalis to different light conditions may be regulated to optimize growth.

• 한국교육논총
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• 제40권3호
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• pp.39-65
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• 2019

생성의 입장에서 바라보는 죽음은 소수 교육철학의 형성에 기여한다. 소수 문학에 대한 탐구는 이 관계를 확고하게 해준다. 들뢰즈와 가타리의 소수 문학이란 소수 언어로 쓰인 문학을 말하는 것이 아니라 오히려 소수자들이 다수언어로 만들어내는 문학을 말한다. 그들은 카프카의 작품들을 그 전형으로 내세운다. 카프카의 작품들은 궁극적으로 이 생성(devenir)으로서의 죽음을 말한다. 죽음과 소수 문학은 강도(intensité)라는 이론적 도구를 공유함으로써 서로를 전제하는 것으로 파악된다. 소수 교육철학은 이런 주장을 좇아 그 가능성이 제기된다. 이는 잘 포장된 상품으로서의 지식을 전달하는 일에만 만족하는 현대 교육철학자들의 정체성에 의문을 제기하고, 특정한 방식으로만 철학자들을 독해하도록 강요하는 주류 교육철학에 맞선다. 우리는 이 가능성을 정동(affect)으로서의 언어에 입각한 교육활동을 통해 제기해 볼 수 있다.

• Journal of Oral Medicine and Pain
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• 제39권4호
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• pp.133-139
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• 2014

Purpose: There have been reports regarding the various factors associated with the level of discomfort and recovery from neurosensory symptoms in patients with trigeminal nerve injury. However, the contributing factors remain uncertain and poorly understood. The purpose of this paper was to investigate the possible association between various factors expected to affect neurosensory discomfort and recovery in patients with mandibular nerve injury after dental implant surgery. Methods: Eighty-nine post-dental implant surgery patients with mandibular nerve injury were enrolled in this retrospective analysis. A medical records review of the patients was done to determine if the patients' improvement was related to pain intensity, the length of time between the injury and removal of the implant or the depth of penetration of the implant into the mandibular canal as determined by cone-beam computed tomography. Results: There was no significant linear relationship between pain intensity and symptomatic improvement (p=0.319). There was no significant linear relationship between the level of mandibular canal penetration and either pain intensity (p=0.588) or symptomatic improvement (p=0.760). There was a statistically significant linear relationship between length of time before the injury was treated, both with pain intensity (p=0.004), and symptomatic improvement (p=0.024). Conclusions: Our findings indicate that the length of time between nerve injury and initiation of conservative treatment is more closely related to the pain intensity and symptomatic improvement than other factors, including the level of mandibular canal invasion. Additionally, increased pain intensity and decreased symptomatic improvement can be expected over time, because of this linear trend. Therefore, although direct injury to the nerve is the most important factor contributing to a neurosensory disturbances, early neurosensory assessment and initiation of conservative treatment should be done to optimize recovery.

• 대한간호학회지
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• 제29권6호
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• pp.1254-1262
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• 1999

The purpose of this study was to examine the effects of 6-wk low intensity exercise program on fatigue, perceived health state, exercise-related affect, perceived benefits, and exercise self-efficacy for female college student's. The subjects of the study consisted of thirty-four female college students. The research subjects were assigned to experimental and control group. The experimental group participated in 13-17 and 30-60 minute sesseions of exercise program over 6 weeks. Data analysis was done by t-test with SAS program. The results of this study are as follows. 1) The first hypothesis, “The fatigue of experimental group will be lower than control group”, was supported. 2) The second hypothesis, “The perceived health state of experimental group will be higher than control group”, was not supported. 3) The third hypothesis, “The exercise-related affect of experimental group will be higher than control group”, was not supported. 4) The fourth hypothesis, “The benefits of exercise of experimental group will be higher than control group”, was not supported. 5) The fifth hypothesis, “The self-efficacy for exercise of experimental group will be higher than control group”, was supported.