• 전자공학회논문지C
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• 제34C권7호
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• pp.9-17
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• 1997

This paper proposes a routing model based on the HVHD for four-layer routing problems. Differing from the HVHV and HVHH models, the proposed HVHD model permits diagonal routing on the fourth laye rwith a grid of 45.deg., 90.deg. and 135.deg. directions. The developed algorithm which uses a channel-graph including weights routes a layer using diagonal model and the othe rthree layers using HVH model. Applications to several benchmark examples verify that approximately 10~25 percent reduction of channel density can be achieved compared to the conventional four-layer channel routing algorithms.

• Computers and Concrete
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• 제12권5호
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• pp.697-715
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• 2013

Numerous studies have been conducted to understand the shear behavior of reinforced concrete (RC) beams since it is a complex phenomenon. The diagonal cracking strength of a RC beam is critical since it is essential for determining the minimum amount of stirrups and the contribution of concrete to the shear strength of the beam. Most of the existing equations predicting the diagonal cracking strength of RC beams are based on experimental data. A powerful computational tool for analyzing experimental data is an artificial neural network (ANN). Its advantage over conventional methods for empirical modeling is that it does not require any functional form and it can be easily updated whenever additional data is available. An ANN model was developed for predicting the diagonal cracking strength of RC slender beams without stirrups. It is shown that the performance of the ANN model over the experimental data considered in this study is better than the performances of six design code equations and twelve equations proposed by various researchers. In addition, a parametric study was conducted to study the effects of various parameters on the diagonal cracking strength of RC slender beams without stirrups upon verifying the model.

• Journal of the Korean Statistical Society
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• 제21권2호
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• pp.179-185
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• 1992

A model is proposed for describing agreement between two raters on a nominal categorical scale. This model has a structure of symmetry plus main-diagonal equiprobability, which is a special case of the quasi-symmetry model. An example is given.

• Journal of Chest Surgery
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• 제35권1호
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• pp.1-10
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• 2002

배경 : 관상동맥 결찰법에 의한 만성 심부전 모델은 실험 사망률이 비교적 높음에도 불구하고 임상적 연관성때문에 지속적인 연구 대상이 된다. 특히 대동물에서 만성 심부전 모델 확립은 소동물에서는 검증할 수 없는 기계 또는 생물학적 순환보조시스템의 연구분석에 대단히 유용하게 사용될 수 있다 이런 관점에서 본연구는 양에서 homonymous artery(사람의 좌전하행지에 해당)와 diagonal branch를 순차적으로 결찰 하는 방법으로 신뢰성 있는 만성 심부전 모델을 확립하고자 하였다. ·재료 및 방법: 모두 9마리의 Corridale 양을 사용하였다. 2마리 양에서 homonymous artery 와 diagonal branch를 동시에 결찰 하였고 7마리에서는 homonymous artery와 diagonal branch를 1시간 간격으로 결찰 하였다. 좌전 개흉술로 심장을 노출시킨 후 심첨부에서 기저부까지의 거리를 기준으로 하여 심첨부에서 40% 위치에서 homonymous artery를 결찰 하였다. diagonal branch는 homonymous artery와 동일한 위치에서 결찰 하였다. 관상동맥 결찰 전, homonymous artery 결찰 후,그리고 diagonal branch 추가 결찰 후 각각 동맥압, 심전도, 그리고 thermodilution catheter로 중심정맥압, 폐동맥압, 폐동맥쐐기압, 심박출량을 측정하였다. 같은 시점에 초음파 검사를 통해 좌심실 이완말기 크기, 좌심실수축말기 크기, 좌심실 구혈률, 좌심실 벽두께, 좌심실 구획단축률과 좌심실 벽운동을 분석하였다. 실험 동물은 2개월 또는 3개월 사육한 뒤 같은 분석 과정을 거친 후 희생시켰다. 실험양의 심장은 적출하여 병리조직학적 검사를 하였다. 결과 Homonymous artery 와 diagonal branch를 동시에 결찰 한 2마리는 결찰 직후 모두 사망하였다. 반면 homonymous artery 와 diagonal branch를 순차적으로 결찰 한 7마리는 모두 생존하였는데 이중 5마리는 2개월 그리고 2마리는 3개월 사육후 심장을 적출하였다. 결찰 2~3개월 후 양에서 중심정맥압, 폐동맥압, 폐동맥쐐기압, 좌심실 이완말기 및 수축말기 크기의 유의한 증가가 관찰되었다(p<0.05) 반면 homonymous artery 결찰 직후에는 동맥압의 유의한 감소(p<0.05)가 diagonal branch의 추가 결찰 후에는 동맥압, 심박출량의 감소 및 폐동맥쐐기압의 유의한 증가가 관찰되었다(p<0.05). 좌심실 벽운동은 결찰 직후부터 다양한 정도의 anteroseptal akinesia또는 dyskinesia가 관찰되었다. 적출 심장의 병리 분석 결과 주위와 잘 구별되는 섬유화 경색 부위가 관찰되었다. 결론: 양에서 homonymous artery와 diagonal branch를 순차적으로 결찰하는 방법으로 신뢰성 있는 만성 심부전 모델을 확립할 수 있었다.

• 한국해양공학회지
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• 제21권6호
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• pp.7-15
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• 2007

A mechanical model was developed to predict the behavior of point-loaded RC slender beams (a/d > 2.5) without stirrups. It is commonly accepted by most researchers that a diagonal tension crack plays a predominant role in the failure mode of these beams, but the failure mechanism of these members is still debatable. In this paper, it was assumed that diagonal tension failure was triggered by the concrete cover splitting due to the dowel action at the initial location of diagonal tension cracks, which propagate from flexural cracks. When concrete cover splitting occurred, the shape of a diagonal tension crack was simultaneously developed, which can be determined from the principal tensile stress trajectory. This fictitious crack rotates onto the crack tip with load increase. During the rotation, all forces acting on the crack (i.e, dowel force of longitudinal bars, vertical component of concrete tensile force, shear force by aggregate interlock, shear force in compression zone) were calculated by considering the kinematical conditions such as crack width or sliding. These forces except for the shear force in the compression zone were uncoupled with respect to crack width and sliding by the proposed constitutive relations for friction along the crack. Uncoupling the shear forces along the crack was aimed at distinguishing each force from the total shear force and clarifying the failure mechanism of RC slender beams without stirrups. In addition, a proposed method deriving the dowel force of longitudinal bars made it possible to predict the secondary shear failure. The proposed model can be used to predict not only the entire behavior of point-loaded RC slender shear beams, but also the ultimate shear strength. The experiments used to validate the proposed model are reported in a companion paper.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제17권7호
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• pp.1841-1857
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• 2023

CenterNet, a novel object detection algorithm without anchor based on key points, regards the object as a single center point for prediction and directly regresses the object's height and width. However, because the objects have different sizes, directly regressing their height and width will make the model difficult to converge and lose the intrinsic relationship between object's width and height, thereby reducing the stability of the model and the consistency of prediction accuracy. For this problem, we proposed an algorithm based on the regression of the diagonal half-length and the center angle, which significantly compresses the solution space of the regression components and enhances the intrinsic relationship between the decoded components. First, encode the object's width and height into the diagonal half-length and the center angle, where the center angle is the angle between the diagonal and the vertical centreline. Secondly, the predicted diagonal half-length and center angle are decoded into two length components. Finally, the position of the object bounding box can be accurately obtained by combining the corresponding center point coordinates. Experiments show that, when using CenterNet as the improved baseline and resnet50 as the Backbone, the improved model achieved 81.6% and 79.7% mAP on the VOC 2007 and 2012 test sets, respectively. When using Hourglass-104 as the Backbone, the improved model achieved 43.3% mAP on the COCO 2017 test sets. Compared with CenterNet, the improved model has a faster convergence rate and significantly improved the stability and prediction accuracy.

• Structural Engineering and Mechanics
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• 제81권2호
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• pp.131-146
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• 2022

This study highlights the accuracy of several single strut models to predict the global response of infilled reinforced concrete (R/C) frames. To this aim, six experimental tests are selected to calibrate the numerical modeling. The width of the diagonal strut is calculated using several macro models from the literature. The mechanical properties of the diagonal strut are determined by using two methods: (a) by subtracting the bare frame response from that of the infilled frame, and (b) by calculating the axial strength in the diagonal direction. A combination between the different width and the axial force models is carried out to study the effects of each parameter on global response. Non-linear pushover analyses are conducted using SAP2000. The results indicate the accuracy of the macro-modeling approach to predict the behavior of the infilled frames.

• Structural Engineering and Mechanics
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• 제84권1호
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• pp.113-127
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• 2022

Steel plate shear walls (SPSWs) are commonly utilized to provide lateral stiffness in high-rise structures. The simplified model is frequently used instead of the fine-scale model in the design of buildings with SPSWs. To predict the lateral strength of steel plate shear walls with diagonal stiffeners (DS-SPSWs), a simplified model is presented, namely the cross brace-strip model (CBSM). The bearing capacity and internal forces of columns for DS-SPSWs are calculated. In addition, a modification coefficient is introduced to account for the shear action of the thin plate. The feasibility of the CBSM is validated by comparing the numerical results with theoretical and experimental results. The numerical results from the CBSM and fine-scale model, which represent the bearing capacity of the DS-SPSW with varied stiffened plate dimensions, are in good accord with the theoretical values. The difference in bearing capacity between the CBSM and the fine-scale model is less than 1.35%. The errors of the bearing capacity from the CBSM are less than 5.67% when compared to the test results of the DS-SPSW. Furthermore, the shear and axial forces of CBSM agree with the results of the fine-scale model and theoretical analysis. As a result, the CBSM, which reflects the contribution of diagonal stiffeners to the lateral resistance of the SPSW as well as the effects on the shear and axial forces of the columns, can significantly improve the design accuracy and efficiency of buildings with DS-SPSWs.

• 유체기계공업학회:학술대회논문집
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• 유체기계공업학회 2002년도 유체기계 연구개발 발표회 논문집
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• pp.137-146
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• 2002

This paper presents a quasi-3-dimensional calculation method considering secondary flows in the impellers of diagonal flow blowers. A Quantitative estimation of the secondary flow effects is made by using secondary flow theories. In order to verify the validity of the adopted models, that is, span-wise mixing model and the tip clearance model, numerical simulations are performed for two different types of impellers of diagonal flow blowers which are designed differently. Numerical experiments are conducted for each of a constant tangential velocity type impeller, and a free vortex type impeller, both at two different flow coefficients. According to the simulation results, it was found that the present model considering span-wise mixing and tip clearance effect shows better agreements with the experimental data than those without these models in terms of the flow velocity and the angle distribution.

• Computers and Concrete
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• 제14권1호
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• pp.19-40
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• 2014

Reinforced concrete deep beams are structural beams with low shear span-to-depth ratio, and hence in which the strain distribution is significantly nonlinear and the conventional beam theory is not applicable. A strut-and-tie model is considered one of the most rational and simplest methods available for shear strength prediction and design of deep beams. The strut-and-tie model approach describes the shear failure of a deep beam using diagonal strut and truss mechanism: The diagonal strut mechanism represents compression stress fields that develop in the concrete web between diagonal cracks of the concrete while the truss mechanism accounts for the contributions of the horizontal and vertical web reinforcements. Based on a database of 406 experimental observations, this paper proposes a new strut-and-tie-model for accurate prediction of shear strength of reinforced concrete deep beams, and further improves the model by correcting the bias and quantifying the scatter using a Bayesian parameter estimation method. Seven existing deterministic models from design codes and the literature are compared with the proposed method. Finally, a limit-state design formula and the corresponding reduction factor are developed for the proposed strut-andtie model.