통행 단말기 정보를 이용한 동적 기종점 통행량 추정모형 개발 및 적용에 관한 연구

임용택,추상호,강민구 대한교통학회 2008 대한교통학회지 Vol.26 No.6

ynamic origin-destination (OD) trip matrix has been widely used for transportation fields such as dynamic traffic assignment, traffic operation and travel demand management, which needs precise OD trip matrix to be collected. This paper presents a quasi-dynamic OD matrix estimation model and applies it to real road network for collecting the dynamic OD matrix. The estimation model combined with dynamic traffic assignment program, DYNASMART-P, is based on GPS embedded in PDA, which developed for collecting sample dynamic OD matrix. The sample OD matrix should be expanded by the value of optimal sampling ratio calculated from minimization program. From application to real network of Jeju, we confirm that the model and its algorithm produce a reasonable solution. 동적(dynamic) 기종점(origin-destination, OD) 통행량은 다양한 교통분야에 활용이 가능한데, 대표적으로 동적 통행배정모형의 입력자료와 같은 교통계획분야와 실시간 도로교통 운영분야, 그리고 교통수요 관리분야 등에도 사용할 수 있다. 이런 교통정책들을 평가하기 위해서는 정확한 동적 OD통행량의 추정은 무엇보다 중요하며, 이를 위하여 다양한 기법들이 제시되고 있다. 본 연구에서는 최근 새롭게 연구되고 있는 개인이 소지한 통행 단말기 정보를 이용하여 동적 OD통행량을 추정하고 이를 평가하고자 한다. 이를 위하여 동적 OD추정모형을 개발하고 개발된 추정모형과 동적 통행배정모형(DYNASMART-P)을 이용하여 동적 OD통행량을 추정하는데, 동적OD통행량 추정시 이용되는 단말기 정보가 표본자료(sample data)이기 때문에 이를 전수화하는 과정이 포함된다. 본 연구에서 제안한 방법으로 제주시를 대상으로 동적OD통행량을 추정한 결과, 그 가능성을 확인할 수 있었다.

Dynamic Cost-sensitive Ensemble Classification based on Extreme Learning Machine for Mining Imbalanced Massive Data Streams

Yuwen Huang 보안공학연구지원센터(IJUNESST) 2015 International Journal of u- and e- Service, Scienc Vol.8 No.1

In order to lower the classification cost and improve the performance of the classifier, this paper proposes the approach of the dynamic cost-sensitive ensemble classification based on extreme learning machine for imbalanced massive data streams (DCECIMDS). Firstly, this paper gives the method of concept drifts detection by extracting the attributive characters of imbalanced massive data streams. If the change of attributive characters exceeds threshold value, the concept drift occurs. Secondly, we give Cost-sensitive extreme learning machine algorithm, and the optimal cost function is defined by the dynamic cost matrix. Build the cost-sensitive classifiers model for imbalanced massive data streams under MapReduce, and the data streams are processed in parallel. At last, the weighted cost-sensitive ensemble classifier is constructed, and the dynamic cost-sensitive ensemble classification based on extreme learning machine classification is given. The experiments demonstrate that the proposed ensemble classifier under the MapReduce framework can reduce the average misclassification cost and can make the classification results more reliable. DCECIMDS has high performance by comparing to the other classification algorithms for imbalanced data streams and can effectively deal with the concept drift.

Tracing the Origin of the Anomalous Matrix Suppression in Matrix-assisted Laser Desorption Ionization and Extending the Linear Dynamic Range During Analyte Quantification

송효인,현택환,김명수,오주연,문정희 대한화학회 2018 Bulletin of the Korean Chemical Society Vol.39 No.2

In the matrix-assisted laser desorption ionization-based quantification method developed in this laboratory, a linear calibration curve is constructed by plotting the analyte-to-matrix ion abundance ratio as a function of the analyte concentration. As the analyte concentration increases, however, the curve deviates from linearity. Previously, we observed that the occurrence of this deviation correlated with the decrease in the matrix ion signal, or matrix suppression. In this work, we found that saturation of the detector was one of the factors responsible for the above phenomena. As we decreased the detector gain, the upper limit of the linear dynamic range increased by as much as one order of magnitude. Even after a substantial decrease in the detector gain, however, the nonlinearity remained at a high analyte concentration, which we cannot account for at present. The method developed in this work can be useful for the quantitative imaging of analytes in heavily contaminated samples.

A Novel Dynamic Index of Voltage Instability Expectation with Power System Contingency

Duy-Phuong N. Do,오웅진,이연찬,최재석,이병준 대한전기학회 2019 Journal of Electrical Engineering & Technology Vol.14 No.4

This paper proposes a novel dynamic voltage instability expectation index which takes into account dynamic voltage stability characteristics, the long-term phenomena and probability state of power system contingency. This index is a meter to measure the general robust power system under critical cases which are identifi ed by contingency analysis. The critical contingencies are precisely analyzed by steady-state power load fl ow in perturbations to fi gure out violation cases, the weakness of the power system. The probability states of each of violation cases are calculated through availability and unavailability values of devices. The degree of voltage instability is estimated newly by the smallest determinant of dynamic load fl ow Jacobian matrix in evolution time of power system simulation. The variables of dynamic devices such as under load tap changer of the transformer, excitation limiters of generator unit, aff ected on a long-term characteristic of the power system, are considered in dynamic load fl ow Jacobian matrix. Combining the voltage instability rate and the probability state, a novel index, namely voltage instability expectation in dynamic index, is proposed. This index refl ects the mutual correlation between the voltage instability rate and probable contingency cases which result in either voltage violation, overload fl ow, or voltage instability. The new index is demonstrated in IEE 9-bus test system and actual Vietnam power system. It should be a new measure to make a decision of transmission system expansion planning.

Dynamic analysis of trusses including the effect of local modes

Levy, Eldad,Eisenberger, Moshe Techno-Press 1999 Structural Engineering and Mechanics, An Int'l Jou Vol.7 No.1

The dynamic analysis of trusses using the finite element method tends to overlook the effect of local member dynamic behavior on the overall response of the complete structure. This is due to the fact that the lateral inertias of the members are omitted from the global inertia terms in the structure mass matrix. In this paper a condensed dynamic stiffness matrix is formulated and used to calculate the exact dynamic properties of trusses without the need to increase the model size. In the examples the limitations of current solutions are presented together with the exact results obtained from the proposed method.

Dynamic analysis of deployable structures using independent displacement modes based on Moore-Penrose generalized inverse matrix

Ping Xiang,Minger Wu,Rui Q. Zhou 국제구조공학회 2015 Structural Engineering and Mechanics, An Int'l Jou Vol.54 No.6

Deployable structures have gained more and more applications in space and civil structures, while it takes a large amount of computational resources to analyze this kind of multibody systems using common analysis methods. This paper presents a new approach for dynamic analysis of multibody systems consisting of both rigid bars and arbitrarily shaped rigid bodies. The bars and rigid bodies are connected through their nodes by ideal pin joints, which are usually fundamental components of deployable structures. Utilizing the Moore-Penrose generalized inverse matrix, equations of motion and constraint equations of the bars and rigid bodies are formulated with nodal Cartesian coordinates as unknowns. Based on the constraint equations, the nodal displacements are expressed as linear combination of the independent modes of the rigid body displacements, i.e., the null space orthogonal basis of the constraint matrix. The proposed method has less unknowns and a simple formulation compared with common multibody dynamic methods. An analysis program for the proposed method is developed, and its validity and efficiency are investigated by analyses of several representative numerical examples, where good accuracy and efficiency are demonstrated through comparison with commercial software package ADAMS.

Matrix-strength-dependent strain-rate sensitivity of strain-hardening fiber-reinforced cementitious composites under tensile impact

Park, Jun Kil,Kim, Sung-Wook,Kim, Dong Joo Elsevier 2017 COMPOSITE STRUCTURES -BARKING THEN OXFORD- Vol.162 No.-

<P><B>Abstract</B></P> <P>The effects of matrix strength on the rate-sensitive tensile responses of strain-hardening fiber-reinforced cementitious composites (SH-FRCCs) at high strain rates were investigated using an improved strain energy frame impact machine (I-SEFIM) overcoming the limitations of previous strain energy frame impact machine (SEFIM). The strengths of matrix were 56, 81, and 180MPa, while 1% long (30mm) hooked and 1% short (13mm) smooth steel fibers were blended in all matrices. Dynamic increase factors (DIFs) for the tensile parameters of the SH-FRCCs, as the strain rate increased, were clearly dependent on the matrix strength although they generally increased: a lower strength matrix produced higher DIFs for both the strain capacity and peak toughness, whereas a higher strength matrix generated higher DIFs for the post-cracking tensile strength. Besides, DIF equations were newly proposed for predicting the post-cracking strength.</P>

전달행렬법을 이용한 집중 질량 진자형 원심진자 흡진기 검토

곽규빈(Gyubin Kwak),이형일(Hyeong-ill Lee) 한국소음진동공학회 2021 한국소음진동공학회 논문집 Vol.31 No.1

The transfer matrix for a simple centrifugal pendulum absorber (CPA) is defined using the vector-type four-pole parameter method. The matrix is validated by comparing the angular accelerance of the absorber obtained by the transfer-matrix method (TMM) adopting derived matrix with the angular accelerance from the traditional method using inertia, stiffness, and damping matrices. Then, TMM is used to calculate the angular displacement transmissibility of a base excited 2-degree-of-freedom system. The optimal configuration of the CPA is investigated using the transfer matrix derived in the first step. The displacement transmissibility of the system modified by the CPA is compared with that of the original system to determine the effect of the CPA. Finally, the displacement transmissibility of a system modified by the CPA is compared with that of the system using a classical dynamic absorber. The results indicate that the transfer matrix introduced in this study can be utilized to investigate the performance of the given CPA and determine the optimal configuration of the CPA for the given requirements.

동특성 변화를 이용하여 트러스 구조물의 손상 예측

이정윤(Jung Youn Lee) 한국소음진동공학회 2020 한국소음진동공학회 논문집 Vol.30 No.1

In this paper, a method for accurately predicting truss damage from dynamic changes before and after the damage occurs is proposed. This method is used to analyze sensitivity coefficients based on changes in dynamic characteristics and detect the damage using a modified stiffness matrix. This matrix is obtained using an iterative method of the sensitivity coefficient matrix, and a method to estimate the location of the damage and the degree of truss damage is developed. The proposed method was applied to a seven-bar truss to predict the location and size of damage accurately.

전달행렬법을 사용하여 균열이 있는 티모센코 보의 동특성 해석

김정호(Jung Ho Kim),곽종훈(Jong Hoon Kwak),이정우(Jung Woo Lee),이정윤(Jung Youn Lee) 한국소음진동공학회 2016 한국소음진동공학회 논문집 Vol.26 No.2

This paper presents a numerical method that can evaluate the effect of crack for the in-plane bending vibration of Timoshenko beam. The method is a transfer matrix method that the element transfer matrix is deduced from the element dynamic stiffness matrix. An edge crack is expressed as a rotational spring, and then is formulated as an independent transfer matrix. To demonstrate the accuracy of this theory, the results computed from the present are compared with those obtained from the commercial finite element analysis program. Based on these comparison results, a parametric study is performed to analyze the effects for the size and locations of crack.