• 대한교통학회지
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• 제27권3호
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• pp.91-102
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• 2009

도로설계 안전성을 평가하기 위해서는 도로의 설계 요소변화가 사고에 미치는 영향을 예측할 수 있어야 한다. 이를 위해 본 연구에서는 통계적 방법, 사고이력, 전문가의 판단, 그리고 기존문헌고찰 등 다양한 방법을 통하여, 설계요소의 특징과 사고율 및 사고빈도의 관계를 반영할 수 있는 AMF(Accident Modification Factor)를 개발하고자 하였다. 본 연구에서는 AMF를 좌회전전용차로, 우회전전용차로, 시거, 교차각 등의 항목을 대상으로 개발하였다. 개발된 AMF를 적용한 경우의 사고 예측값, 사고예측모형을 통한 예측값을 실제 사고데이터와 비교분석함으로써 적정성을 검토하였다. 분석결과, AMF를 적용한 예측값이 사고예측모형을 통한 예측 값보다 예측력이 우수함을 확인할 수 있었다. 이러한 결과는 사고를 예측함으로써 도로설계 안전성을 평가하는 알고리즘에 있어 AMF가 도로의 설계요소의 특성을 보다 효과적으로 반영하며, 지방부 교차로에서 각각의 해당요소가 사고에 미치는 영향을 판단할 수 있는 지표가 될 수 있음을 의미한다.

• 한국도로학회논문집
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• 제15권6호
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• pp.113-123
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• 2013

PURPOSES : Although numerous researches have been studied to reveal accident causations for road intersections, there are still many research gaps for road segments. It is mainly because of difficulty of data and lack of analytical method. This study aims to study accident causations for rural road segments and develop accident modification factors for safety evaluation. The accident modification factors can be used to improve road safety. METHODS : Methods for developing AMF are diverse. This study developed AMFs using accident prediction models and selected explanatory variables from the accident models. In order to select final AMFs, three different methods were applied in the study. RESULTS : As a result of the study, many AMFs such as horizontal curves or vertical curves were developed and explained the meanings of the results. CONCLUSIONS : This study introduced meaningful methods for developing significant AMFs and also showed several AMFs. It is expected that traffic or road engineers will be able to use the AMFs to improve road segment safety.

• 대한화학회지
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• 제68권2호
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• pp.107-116
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• 2024

본 연구의 목적은 테크놀로지를 활용한 모델의 평가와 수정 과정에서 나타난 예비화학교사들의 모델의 본성에 대한 인식 변화를 분석하는 것이다. 모델의 본성에 대한 인식 변화는 선행연구에서 예비화학교사들에게 부족하다고 판단된 표상적 측면의 함축화와 간단화, 설명적 측면의 해석, 추론, 설명, 정량화를 중심으로 분석하였다. 이를 위하여 충청북도에 있는 사범대학의 3학년 예비화학교사 19명을 대상으로 테크놀로지를 활용하여 개발한 보일 법칙 관련 모델을 평가하고, 평가 결과를 바탕으로 모델을 수정하여 최종 평가하도록 요구하였다. 연구 결과, 표상적 측면의 간단화, 설명적 측면의 해석, 설명, 정량화에 대한 예비화학교사들의 인식이 모델의 평가와 수정 과정을 통해 긍정적으로 변화되었음을 확인할 수 있었다. 따라서 모델의 본성에 대한 인식이 변화하기 위해서는 모델의 평가와 수정 과정이 핵심적인 역할을 하는 것을 알 수 있었다. 하지만 표상적 측면의 함축화와 설명적 측면의 추론에 대한 인식 변화는 거의 나타나지 않았다. 이러한 요소들에 대한 인식은 다른 요소들의 인식보다 변화하기 어려운 것으로 볼 수 있다. 이러한 문제를 해결하기 위해서는 예비화학교사들을 위한 보다 정교한 교육 설계가 필요하다.

• 한국지진공학회논문집
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• 제20권4호
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• pp.211-222
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• 2016

Reinforced concrete shear walls with deficient reinforcement details are tested under cyclic loading. The deficiency of reinforcement details includes insufficient splice length in U-stirrups at the ends of horizontal reinforcement and boundary column dowel bars found in existing low- to mid-rise Korean buildings designed non-seismically. Three test specimens have rectangular, babel and flanged sections, respectively. Flexure- and shear-controlled models for reinforced concrete shear walls specified in ASCE/SEI 41-13 are compared with the flexural and shear components of force-displacement relation extracted separately from the top displacement of the specimen based on the displacement data measured at diverse locations. Modification of the shear wall models in ASCE/SEI 41-13 is proposed in order to account for the effect of bar slip, cracking loads in flexure and shear. The proposed modification shows better approximation of the test results compared to the original models.

• 한국생산제조학회지
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• 제19권2호
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• pp.178-183
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• 2010

Base-mounted type(BMT) driving assembly in CNC machine tools is an indispensable part to improve productivity by reducing tool changeover time and to meet the ever-increasing demand of precision machine tools. This study aimed to perform finite element analysis and geometric parameter optimization to improve the efficiency of BMT driving assembly. First, simulations for three-dimensional structural and vibration analysis were performed using ANSYS/Workbench on the initial geometric models of BMT driving assembly. After analyzing stress and deformation concentration zones, several new geometrical models were designed and evaluated by design of experiments and ANSYS/DesignXplorer. Through a series of analysis-evaluation-modification cycles, it was seen that designed models were effective in determining optimal geometry of BMT driving assembly.

• Journal of Ginseng Research
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• 제48권3호
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• pp.298-309
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• 2024

Background: 20(S)-ginsenoside Rh2(GRh2), an effective natural histone deacetylase inhibitor, can inhibit acute myeloid leukemia (AML) cell proliferation. Lactate regulated histone lactylation, which has different temporal dynamics from acetylation. However, whether the high level of lactylation modification that we first detected in acute promyelocytic leukemia (APL) is associated with all-trans retinoic acid (ATRA) resistance has not been reported. Furthermore, Whether GRh2 can regulate lactylation modification in ATRA-resistant APL remains unknown. Methods: Lactylation and METTL3 expression levels in ATRA-sensitive and ATRA-resistant APL cells were detected by Western blot analysis, qRT-PCR and CO-IP. Flow cytometry (FCM) and APL xenograft mouse models were used to determine the effect of METTL3 and GRh2 on ATRA-resistance. Results: Histone lactylation and METTL3 expression levels were considerably upregulated in ATRA-resistant APL cells. METTL3 was regulated by histone lactylation and direct lactylation modification. Overexpression of METTL3 promoted ATRA-resistance. GRh2 ameliorated ATRA-resistance by downregulated lactylation level and directly inhibiting METTL3. Conclusions: This study suggests that lactylation-modified METTL3 could provide a promising strategy for ameliorating ATRA-resistance in APL, and GRh2 could act as a potential lactylation-modified METTL3 inhibitor to ameliorate ATRA-resistance in APL.

• Earthquakes and Structures
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• 제12권6호
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• pp.643-652
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• 2017

One of the methods to strengthen the structures against the seismic lateral loading is the employment of the composite columns. A concrete-filled tube (CFT) has the cumulative advantages of steel and concrete. Concrete-filled steel tube columns have been widely used in the moment-resisting frame (MRF) structures, located in both non-seismic zones and high-risk seismic zones. In this paper, the results of studies on two important seismic parameters of ductility and the response modification factor (RMF) of the MRFs with CFT columns are submitted. While the studies are carried out, the effects of span length-story height ratio, the strength of materials and seismic behavior of MRFs are considered. In this regard, the ductility, RMF and the strength of 36 models of the steel MRFs with CFTs are analyzed. The fiber plastic hinges numerical simulation and pushover analysis method are used in the calculations. Based on the obtained results, the RMFs suitable for the 5-, 10- and 15- story frames are proposed.

• 한국지진공학회논문집
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• 제17권1호
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• pp.11-19
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• 2013

This research presents that seismic performance of steel moment resisting frame building designed by past provision(UBC, Uniform Building Code) before and after retrofitted with BRB (Buckling-Restrained Brace) was evaluated using response modification factor (R-factor). In addition, the seismic performance of the retrofitted past building was compared with that specified in current provision. The past building considered two different connections: bilinear connection, which was used by structural engineer for building design, and brittle connection observed in past earthquakes. The nonlinear pushover analysis and time history analysis were performed for the analytical models considered in this study. The R-factor was calculated based on the analytical results. When comparing the R-factor of the current provision with the calculated R-factor, the results were different due to the hysteresis characteristics of the connection types. After retrofitted with BRBs, the past buildings with the bilinear connection were satisfied with the seismic performance of the current provision. However, the past buildings with the brittle connection was significantly different with the R-factor of the current provision.

• 한국멀티미디어학회논문지
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• 제23권6호
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• pp.729-737
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• 2020

Screening with low-dose spiral computed tomography (LDCT) has been shown to reduce lung cancer mortality by about 20% when compared to standard chest radiography. One of the problems arising from screening programs is that large amounts of CT image data must be interpreted by radiologists. To solve this problem, automated detection of pulmonary nodules is necessary; however, this is a challenging task because of the high number of false positive results. Here we demonstrate detection of pulmonary nodules using six off-the-shelf convolutional neural network (CNN) models after modification of the input/output layers and end-to-end training based on publicly databases for comparative evaluation. We used the well-known CNN models, LeNet-5, VGG-16, GoogLeNet Inception V3, ResNet-152, DensNet-201, and NASNet. Most of the CNN models provided superior results to those of obtained using customized CNN models. It is more desirable to modify the proven off-the-shelf network model than to customize the network model to detect the pulmonary nodules.

• 고려인삼학회:학술대회논문집
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• 고려인삼학회 2002년도 학술대회지
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• pp.1-19
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• 2002

The use of herbals has increased considerably while their efficacy and safety remain untested. This unsupported surge in demand has prompted a call for their clinical evaluation. One area in which evaluations are emerging is ginseng and diabetes. Growing evidence is accumulating from in vitro and animal models indicating that various ginseng species, American (Panax quinquefolius L), Asian (Panax ginseng C.A. Meyer), Korean Red, San-chi (Panax notoginseng [Burk.] P.R. Chen), and the non-panax species Siberian (Eleutherococcus senticossus) ginsing, and their fractions, saponins (ginsenosides) and peptidoglycans (panaxans for panax species and eleutehrans for Siberian ginseng), might affect carbohydrate metabolism and related signaling molecules. Recent human studies from our laboratory have also shown a blood glucose lowering effect of American ginseng (AG) and some other ginseng spices postprandially after acute administration and chronically after administration for 8-weeks in people with type 2 diabetes. Although generally encouraging, these data only indicate a need for more evaluations of ginsengs safety and efficacy. Because of poor industry standardization, it is not known whether all ginsengs will affect blood glucose. In this regards some ginseng batches have demonstrated null effects while others have even raised postprandial glycemia. Clinical research should therefore focus on components involved in its glucose lowering effects.