• 한국정밀공학회지
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• 제12권5호
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• pp.18-24
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• 1995

Drilling chatter is regenerative type self-excited vibration and can be predicted by the measurments of the dynamic compliance between tool and workpiece based on structural dynamics and cutting dynamics. This paper describes the theoretical prediction about drilling chatter and the mechanism of the formation of multi-coner shape in holes by drilling chatter. By the experiments and theoretical study, it is found that the odd number of multi-coner shape is always generated by drilling chatter.

• 한국정밀공학회지
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• 제11권4호
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• pp.38-46
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• 1994

The vibration amplitude of boring bar is generally large at the tool tip, because it has the high length-diameter(L/D) ratio. A new dynamic cutting force model is presented by considering the change of shear angle under dynamic cutting. The boring bar is modelled as a cantilever with dynamic force acting at the tool end point. Based on this realistic continuous system model, the equation of motion of borring bar is solved by numerical computations. A good agreement is found between the proposed model and the experimental results.

• 한국지반공학회논문집
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• 제28권10호
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• pp.89-96
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• 2012

본 연구에서는 사면위험도의 합리적인 평가 가중치를 도출하기 위하여 국내의 대표적인 평가방법에 대해 동일한 영향성을 주는 것으로 간주되는 항목들을 그룹화하여 그 영향성을 분석하고 이를 국립방재연구소(NIDP) 평가법과 비교, 사면붕괴 주요인자 선별의 적정성과 배점비율을 검토하였다. 또한, 붕괴가 발생된 28개소 사면을 대상으로 ANN(Artificial Neural Network) 기법을 적용하여 사면붕괴 유발인자 가중치에 대한 합리적 배점이 이루어졌는지에 대해 고찰하였다. ANN기법에 의해 평가비중을 재조정하여 분석한 결과, 국립방재연구소 평가법의 평가비중 오차가 큰 예상피해도, 인장균열, 계곡부 항목의 가중치를 조정하여야 보다 정확한 평가가 가능할 것으로 분석되었다.

• 한국지반환경공학회 논문집
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• 제17권1호
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• pp.21-28
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• 2016

본 논문은 레일빔의 길이 산정에 관해서 지반공학적 측면에서 다룬 내용을 담고 있다. 레일빔은 철도횡단공사에서 가설기간 중에 부등침하 방지 목적으로 레일의 내측과 외측에 설치하는 보강레일을 말한다. 이러한 레일빔은 최근 철도를 횡단하는 지하 구조물의 시공이 증가해서 기존 철도 시설물의 안정에 대응하고자 많이 설치하고 있다. 그러나 레일빔 길이 설계에 관한 기준이 없어 설계에 어려움이 있을 뿐만 아니라 레일빔 길이 부족으로 탈선사고까지 이어지는 경우가 발생하고 있다. 따라서 본 연구에서는 레일빔 길이 산정 방식에 대하여 토사지반과 암반지반으로 분류하여 Flow chart를 제시하였으며 레일 조합 및 위치에 대한 Case study를 실시하여 효과적인 레일의 조합과 위치에 확보할 수 있었다.

• 대한한방부인과학회지
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• 제36권3호
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• pp.62-77
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• 2023

Objectives: The purpose of this study is to investigate the domestic study trends on habitual abortion treated with Korean medicine. Methods: We searched the studies on habitual abortion treated with Korean medicine via searching 5 Korean web databases. After searching studies, we analyzed 7 studies selected according to the selection and exclusion criteria. Results: Of the seven selected studies, five case-reporting studies and two retrospective chart analysis. The most applied intervention for habitual abortion was herbal medication. All patients took herbal medicine before pregnancy, and Seunggum-dan was widely used. 66.3% of pregnant patients after treatment took herbal medicine after pregnancy, and Anjeonyichen-tang was the most widely used. As a result of analyzing retrospective chart analysis studies, whether the patient's age was 35 years or older has a significant impact on the success rate of Korean medicine treatment. Conclusions: This study has provided a basis for using Korean medical intervention in the treatment of habitual abortion in clinical practice. In order to provide a more high-quality basis, reliable follow-up studies related to the effectiveness and stability of Korean medicine treatment for habitual abortion should be conducted in the future.

• 대한한의학회지
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• 제43권3호
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• pp.139-149
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• 2022

Objectives: This study was designed to investigate the clinical effectiveness of Ikgibohyeol-tang(Yìqìbǔxuè-tāng) granules and Deer antler granules on fatigue symptoms. Methods: This is a 39-patient case series from a retrospective chart review of outpatients who were treated with Ikgibohyeol-tang granules and Deer antler granules at a Kyung Hee University Korean Medicine Hospital (Seoul) between 1st, January 2015 to 1st, August 2021. We reviewed the patients who complained of fatigue and analyzed changes in the degree of discomfort with fatigue and accompanying symptoms and HRV (Heart Rate Variability) score before and after treatment. Results: After taking Ikgibohyeol-tang granules and Deer antler granules, the degree of discomfort with fatigue and accompanying symptoms decreased significantly compared to before taking them. After treatment, Autonomic nervous system activity, Stress resistance, Heart Stability increased, and Stress index, Degree of fatigue decreased significantly. Conclusions: This study showed subjective symptoms and objective indicator (HRV score) were improved by taking Ikgibohyeol-tang granules and Deer antler granules.

• Geomechanics and Engineering
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• 제23권4호
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• pp.313-325
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• 2020

Slope displacement and factor of safety (FOS) of a slope are two aspects that reflect the stability of a slope. However, the traditional limit equilibrium (LE) methods only give the result of the slope FOS and cannot be used to solve for the slope displacement. Therefore, developing a LE method to obtain the results of the slope FOS and slope displacement has significance for engineering applications. Based on a force-displacement coupled mode, this work expands the LE Morgenstern-Price (M-P) method. Except for the mechanical equilibrium conditions of a sliding body adopted in the traditional M-P method, the present method introduces a nonlinear model of the shear stress and shear displacement. Moreover, the energy equation satisfied by a sliding body under a small slope displacement is also applied. Therefore, the double solutions of the slope FOS and horizontal slope displacement are established. Furthermore, the flow chart for the expanded LE M-P method is given. By comparisons and analyses of slope examples, the present method has close results with previous research and numerical simulation methods, thus verifying the feasibility of the present method. Thereafter, from the parametric analysis, the following conclusions are obtained: (1) the shear displacement parameters of the soil affect the horizontal slope displacement but have little effect on the slope FOS; and (2) the curves of the horizontal slope displacement vs. the minimum slope FOS could be fitted by a hyperbolic model, which would be beneficial to obtain the horizontal slope displacement for the slope in the critical state.

• 한국지반공학회논문집
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• 제35권12호
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• pp.45-58
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• 2019

본 연구에서는 강우의 침투에 따른 토사사면의 파괴에 대한 강우강도-지속시간의 강우기준을 평가하기 위하여 수치해석에 의한 파괴시간의 확률론적 해석 절차를 제안하였다. 취약도 곡선은 시간에 따른 강우의 침투해석 결과를 반영하며 지반의 역학적 특성의 불확실성을 고려한 MCS에 의한 확률론적 사면 안정해석의 결과로부터 강우강도-지속기간의 함수로 생성하였다. 확률론적 해석에서 한계상태함수를 계산하기 위하여 강우의 침투해석과 연동된 사면 안정해석을 수행하였다. 생성된 사면의 취약도 곡선들을 기반으로 확률론적 사면 파괴분포 분석을 수행하여 지반의 불확실성을 고려한 사면 파괴 유발 강우기준을 평가하였다. 제안된 사면 파괴분포 분석법은 강우의 침투로 인한 사면 파괴의 과정을 분석하고 사면 파괴가 발생할 수 있는 시간을 예측하는데 유용하게 사용될 수 있다.

• 대한두개안면성형외과학회지
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• 제12권1호
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• pp.12-16
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• 2011

Purpose: This study examined the biomechanical stability of four different plating techniques in the experimental model of mandibular subcondyle fracture. Methods: Twenty standardized bovine tibia bone samples ($7{\times}1.5{\times}1.0cm$) were used for this study. Each of the four sets of tibia bone was cut to mimic a perpendicular subcondyle fracture in the center area. The osteotomized tibia bone was fixed using one of four different fixation groups (A,B,C,D). The fixation systems included single 2.0 mm 4 hole mini adaption plate (A), single 2.0 mm 4 hole dynamic compression miniplate (B), double fixation with 2.0 mm 4 hole mini adaption plate (C), double fixation with a 2.0 mm 4 hole mini adaption plate and 2.0 mm 4 hole dynamic compression miniplate (D). A bending force was applied to the experimental model using a pressure machine (858 table top system, $MTS^{(R)}$) until failure occurred. The load for permanent deformation, maximum load of failure were measured in the load displacement curve with the chart recorder. Results: Double fixation with a 2.0 mm 4 hole mini adaption plate and a 2.0 mm 4 hole dynamic compression miniplate (D) applied to the anterior and posterior regions of the subcondyle experimental model showed the highest load to failure. Conclusion: From this study, double fixation with an adaption plate and dynamic compression miniplate fixation technique produced the greatest biomechanical stability. This technique may be considered a useful means of fixation to reduce the postoperative internal maxillary fixation period and achieve early mobility of the jaw.

• 한국임상약학회지
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• 제5권2호
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• pp.17-31
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• 1995

Pharmacist-managed Anticoagulation Service(ACS) was estabilished and the effectiveness of warfarin monitoring by ACS in maintaining therapeutic INR was evaluated. The primary goal of ACS is to maximize the control of therapy, to maintain therapeutic INR and to decrease morbidity and hospitalization caused by inadequate dosage regimen. Clinical pharmacists performed chartreview, laboratory interpretation, recommendations for warfarin dosage adjustments, physician and patient education, and coordination of follow-up in ACS. Patients receiving warfarin sodium were evaluated via retrospective chart review. Sixty-two patients were referred to ACS by primary physicians were compared with 117 patients in the physician-amtrolled group. The ACS patients maintained $88.6\%$ in the therapeutic range for anticoagulant therapy and the control group maintained $63.7\%$, where the difference was statistically significant.(P<0.001) The ACS improved warfarin dose determination, PT stability, patient compliance and provided improved therapy compared with the control group. ACS offers safe and efficient anticoagulant therapy in the ambulatory setting.