• 한국ITS학회 논문지
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• 제11권2호
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• pp.10-20
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• 2012

본 연구에서는 일반국도 수시조사 지점의 AADT 추정값의 정확도를 높이기 위하여 새로운 그룹핑방법을 제시하였다. 일반적으로 수시조사 자료의 AADT 추정을 위해 월보정계수, 요일보정계수, 조사된 24시간 교통량을 이용하여 AADT를 추정 하므로 상시조사 지점을 그룹핑할 때 상기 세 가지 요인(43개 변수)을 모두 적용하여 그룹핑하였다. 이 방법은 기존의 월보정계수와 요일보정계수만을 이용하여 그룹핑한것과 비교하여 시간대별 교통량을 적용한 것에 있어서 차이가 있다. 그룹핑 결과 5개의 군집이 가장 적당한 것으로 분석되었다. 5개의 군집 중 2개의 군집은 해당되는 지점이 몇 지점 없어 설명하기 어려웠고, 나머지 3개의 군집에서 각각 출퇴근로, 관광부도로, 지방부도로의 특성을 가지는 것으로 나타났다. 각 그룹의 월보정계수 평균과 요일보정계수 평균, 시간대별 교통량 비율의 평균으로 각 그룹의 대표 보정계수를 산출하고, 분석대상지점의 평일 교통량을 해당 그룹의 대표 보정계수를 적용하여 AADT를 추정한 결과 평균적으로 오차가 8.7%인 것으로 나타났다. 이는 기존 연구에서 우수하다고 분석된 동일 대구간 내의 상시조사 보정계수를 적용한 것보다 1.5%오차가 더 적은 것으로 나타났다. 이러한 AADT 산출방법은 전체 수시조사 지점에 적용 가능하므로 실무에서의 활용도가 매우 크다고 판단된다.

• 스마트미디어저널
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• 제9권2호
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• pp.22-32
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• 2020

The hippocampal volume atrophy is known to be linked with neuro-degenerative disorders and it is also one of the most important early biomarkers for Alzheimer's disease detection. The measurements of hippocampal pure volumes from Magnetic Resonance Imaging (MRI) is a crucial task and state-of-the-art methods require a large amount of time. In addition, the structural brain development is investigated using MRI data, where brain morphometry (e.g. cortical thickness, volume, surface area etc.) study is one of the significant parts of the analysis. In this study, we have proposed a patch-based ensemble model of 3-D convolutional neural network (CNN) to measure the hippocampal pure volume from MRI data. The 3-D patches were extracted from the volumetric MRI scans to train the proposed 3-D CNN models. The trained models are used to construct the ensemble 3-D CNN model and the aggregated model predicts the pure volume in one-step in the test phase. Our approach takes only 5 seconds to estimate the volumes from an MRI scan. The average errors for the proposed ensemble 3-D CNN model are 11.7±8.8 (error%±STD) and 12.5±12.8 (error%±STD) for the left and right hippocampi of 65 test MRI scans, respectively. The quantitative study on the predicted volumes over the ground truth volumes shows that the proposed approach can be used as a proxy.

• 무역상무연구
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• 제72권
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• pp.139-160
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• 2016

Using the gravity model, this paper analyzes empirically how the world trade in goods is affected by regional trade agreements(RTAs) which have been spreading rapidly since the mid-1990s. This paper attempt to do the panel data analysis about 174 countries during the period of 1994-2008. These panel data include 157 RTAs. It is meaningful that this paper uses comprehensive data to analyze the net effect of regional trade agreements on the global trade volume. This provides a clue as to the answer to the stumbling block debate raised early in the regional trade agreement. Also, confirming how the participation of the WTO affected the trade volume among the member countries, the WTO-related dummy variables are additionally introduced to this gravity model. And as far as we know, the state system-related variables is first considered in this model. This variable reflects the social and cultural environments of countries as the proxy variable representing the sociocultural homogeneity. In all regressions, joining to the WTO and consistency of the state system have a positive effect on increasing the trade volumes between countries. According to the analysis of RTA trade effects, RTAs, on average, increase the volume of trade within the RTA region by 27%~37%, and decrease the volume of trade between the regional and the non-regional nation by 1.2%~3.4%.Therefore, the net effect of regional trade agreements on the promotion of global welfare is positive. For robustness check, we also introduce the interaction term of the dummy variable which reflects the RTA tightening and the continuous variable which reflects the distance effect. As a result, the RTAs alleviate the trade-decreasing effect which is caused by the distance between the countries.

• 대한교통학회지
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• 제21권3호
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• pp.121-134
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• 2003

횡단보도의 안전성과 교통 소통을 동시에 고려하면서 횡단보도 보행자사고를 감소시키기 위한 방안으로 보행자사고 예측모형이 꾸준히 연구되어 왔으나, 기존의 예측모형에서는 횡단보도 보행자사고의 당사자에 해당하는 보행량이라는 변수를 제대로 반영하지 못하고 있는 실정이다. 실제로 보행량과 관련한 자료가 구축되어 있지 않고. 보행량 추정방법 역시 없는 실정이기 때문이다. 이러한 점에 착안하여 본 연구에서는 기준년도 신호교차로 주변의 토지이용특성과 횡단보도 보행량을 조사하여 횡단보도 보행유출입량 추정모형을 구축하였다. 다음으로, 추정된 횡단보도 보행유출입량을 중력모형의 마찰계수와 구역간 조정계수, 그리고 대각횡단 보행비율을 적용하여 횡단보도 보행경로별로 보행량을 분포시킴으로서 목표년도(보행자사고 발생 시점 또는 장래)의 횡단보도 보행량 추정방법을 제시하였다.

• 한국항해항만학회지
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• 제40권2호
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• pp.57-65
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• 2016

The port throughput situation has changed since the 2008 financial crisis in the US. Therefore, we studied the situation, accurately estimating port traffic of Korean port after the 2008 financial crisis. We ensured the proper port facilities in response to changes in port traffic. In the results of regression analysis, Korean GDP and the real effective exchange rate of Korean Won were found to increase the container throughput in Korean and Busan port, as well as trade volume with China. Also, the real effective exchange rate of Korean Won was found to increase the port transshipment cargo volume. Based on the ARIMA models, we forecasted port throughput and port transshipment cargo volume for the next six years (72 months), from 2015 to 2020. As a result, port throughput of Korean and Busan ports was forecasted by increasing annual the average from about 3.5% to 3.9%, and transshipment cargo volume was forecasted by increasing the annual average about 4.5%.

• 한국인쇄학회지
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• 제14권1호
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• pp.115-131
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• 1996

The PVT(pressure-volume-temperature) relation of main-chain dimer liquid crystals having structures such as $\alpha$,$\omega$-bis[(4,4`-cyanobiphenyl) oxy] alkane(CBA-n with=9, 10) were studied. these dimer liquid crystals are known to form an enantiotropic nematic mesophase. In this work, we have determined the volume change as a function of temperature and pressure by using a GNOMIX PVT apparatus. In the V-Tcurves obtaind from isobaris mearements on various pressures, volume changes were observed at the nematic-isotropiz and nematic-crystal phase transitions. The volume changes at the transition exhibit slight odd-even effect with respect to the number of methylene unit n. The values of the (S)v obtained at the NI transition for CBA-9 and -10 were 6.9 and 12.6J/mol k. The valuesof (S)v for the CN transition were estimated on the basis of DSC(differential scanning calorimetry) data: 58.8(CBA-9) and 65.3J/mol k (CBA-10). For both transition, it was found that the correction about the volume change is significant, ranging from 40% to 60% of the total transition entropy observed under constant pressure.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2005년도 ICCAS
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• pp.2402-2406
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• 2005

A collision query determines the intersection between given objects, and is used in computer-aided design and manufacturing, animation and simulation systems, and physically-based modeling. Bounding volume hierarchies are one of the simplest and most widely used data structures for performing collision detection on complex models. In this paper, we present hierarchy of oriented rounded bounding volume for fast proximity queries. Designing hierarchies of new bounding volumes, we use to combine multiple bounding volume types in a single hierarchy. The new bounding volume corresponds to geometric shape composed of a core primitive shape grown outward by some offset such as the Minkowski sum of rectangular box and a sphere shape. In the experiment of parallel close proximity, a number of benchmarks to measure the performance of the new bounding box and compare to that of other bounding volumes.

• 한국전산유체공학회지
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• 제20권1호
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• pp.57-64
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• 2015

This paper describes a volume of fluid(VOF) method, mRHRIC for the simulation of free surface flows around ship hulls and provides its validation against benchmark test cases. The VOF method is developed on the basis of RHRIC method developed by Park et al. that uses high resolution differencing schemes to algebraically preserve both the sharpness of interface and the boundedness of volume fraction. A finite volume method is used to solve the governing equations, while the realizable ${\kappa}-{\varepsilon}$ model is used for turbulence closure. The present numerical results of the resistance performance tests for DTMB5415 and KCS hull forms show a good agreement with available experimental data and those of other free surface methods.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2006년도 정기 학술대회 논문집
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• pp.891-897
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• 2006

The volume control method which utilize a pressure node added into a finite shell element can overcome the drawbacks of conventional load control method and displacement control method. In this study, an improved volume control method is introduced for effective analysis of path-dependant behaviors of RC structures subjected to cyclic loading. RC shell structures including RC hollow columns are anlayized by discretizing the structures with layered shell elements and by applying in-plane two dimensional constitutive equations for concrete layers and reinforcement layers of the shell elements. The so-called path dependant volume control method is verified by comparing analysis results with other data including experimental results.

• Tribology and Lubricants
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• 제17권1호
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• pp.33-39
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• 2001

A method of calculating wear volume is developed using the signal processing technique. The lowpass filter with Fourier transform and the “windowing” are implemented in the method. User-defining feature is also included in determining the cutoff frequency of the low-pass filter and the baseline for the volume integration. Commercial software, MatLab, is used for the programming. Since the method uses the original wear data without simplifying the wear shape, it can give a further accurate result than the previously utilized methods, which often adopted the simplification. It becomes further powerful if the contacting body has a general shape rather than that gives well-formed surface traction (e.g., the Hertzian). The validation of applying the average surface roughness, Ra, to the “windowing” and the baseline for volume integration is discussed.