가산자료모형을 기초로 한 통행행태의 한계효과분석

장태연 대한교통학회 2003 대한교통학회지 Vol.21 No.3

In general, the linear regression model has been used to estimate trip generation in the travel demand forecasting procedure. However, the model suffers from several methodological limitations. First, trips as a dependent variable with non- negative integer show discrete distribution but the model assumes that the dependent variable is continuously distributed between ­∞ and +∞. Second, the model may produce negative estimates. Third, even if estimated trips are within the valid range, the model offers only forecasted trips without discrete probability distribution of them. To overcome these limitations, a poisson model with a assumption of equidispersion has frequently been used to analyze count data such as trip frequencies. However, if the variance of data is greater than the mean, the poisson model tends to underestimate errors, resulting in unreliable estimates. Using overdispersion test, this study proved that the poisson model is not appropriate and by using Vuong test, zero inflated negative binomial model is optimal. Model reliability was checked by likelihood test and the accuracy of model by Theil inequality coefficient as well. Finally, marginal effect of the change of socio-demographic characteristics of households on trips was analyzed. 교통수요예측의 통행발생단계에서 일반적으로 선형회귀모형이 활용되고 있다. 이러한 선형회귀모형은 여러가지 방법론적 한계성과 실용적 지속성을 가지지 못하는 경향을 보인다. 첫째, 종속변수로 이용되는 통행발생의 경우 비음정수(non-negative integer : 0, 1, 2 등)의 이산분포특징을 보이나, 선형회귀모형에서는 종속변수가 연속확률분포 인 정규분포의 특징을 가진 것으로 가정한다. 둘째, 모형이 자료측정에 적용되었을 때 음(-)의 결과를 산정 할 수 있으며, 독립변수의 증감에 따라 결과 값을 너무 높게 혹은 낮게 예측하는 경우가 있다. 셋째, 예측된 값이 정상적인 범위 내에 있을 지라도 예측된 통행수만을 제시 할 뿐, 통행발생빈도에 대한 이산확률분포는 제공하지 않는다. 이같은 한계점을 극복하기 위해 주로 활용되어온 가산자료모형이 포와송모형이다. 그러나, 포와송모형의 경우 자료의 평균과 분산이 동일하다는 가정하에 활용되고 있어 자료상에 과산포가 존재할 경우 오차를 과소평가 할 경향이 높아 모형의 신뢰성에 문제가 발생됨으로 기타 다른 가산자료모형의 적용을 고려해야한다. 연구에서는 과산포검정을 통해 통행발생빈도상에 과산포 존재를 밝혀내고 포와송모형의 부적합함을 제시하였으며 Vuong 검정을 통해 최적의 모형을 선정하였다. 선정된 모형을 대상으로 우도비검정과 Theil 부등계수에 의해 모형의 신뢰도와 정확성을 조사하였다. 최종적으로 가구의 사회경제적 속성의 변화에 따른 통행발생의 변화를 측정하기 위한 민감도 분석을 실시하였다 논문은 2002년 한국학술진흥재단 연구비에 의해 연구됨(KRF-2002-003-B00367).

전주경전철의 문제점과 대안

장태연 열린전북 2003 열린전북 Vol.2003 No.6

Direct and Indirect Effects on Weekend Travel Behaviors

장태연,황지욱 대한토목학회 2009 KSCE Journal of Civil Engineering Vol.13 No.3

The purpose of this study is to determine the causal factors that influence travel behavior. In particular, the joint relationships between trips, activities and activity durations are researched by examining the effects of personal and household attributes. In order to meet this objective, the total, direct and indirect effects of individual attributes on travel behavior are estimated using structural models. The statistical assumption and the interpretations of coefficients in classical causal analysis are similar to those in linear regression models. Specifically, the direct effects, as estimated coefficients, are only offered and interpreted. However, in travel behavior that results from complicated relationships among trips, activities and individual attributes, the indirect effects among factors related to travel behavior cannot be disregarded. The indirect effects through other intervening factors, in addition to the direct effects, may cause the total effect of specified factors on travel behavior. If only the direct effect is considered for analysis, the causal relationships among factors may not be able to be adequately understood. The advantage of using structural models is that they are able to estimate, in addition to direct structural effects, the indirect effects through other intervening factors. The study also assumes that Saturday travel behavior has an effect on Sunday travel behavior. The subdivided indirect effects of the personal and household attributes on trip generation, activity frequency, and activity durations are empirically analyzed in detail. The purpose of this study is to determine the causal factors that influence travel behavior. In particular, the joint relationships between trips, activities and activity durations are researched by examining the effects of personal and household attributes. In order to meet this objective, the total, direct and indirect effects of individual attributes on travel behavior are estimated using structural models. The statistical assumption and the interpretations of coefficients in classical causal analysis are similar to those in linear regression models. Specifically, the direct effects, as estimated coefficients, are only offered and interpreted. However, in travel behavior that results from complicated relationships among trips, activities and individual attributes, the indirect effects among factors related to travel behavior cannot be disregarded. The indirect effects through other intervening factors, in addition to the direct effects, may cause the total effect of specified factors on travel behavior. If only the direct effect is considered for analysis, the causal relationships among factors may not be able to be adequately understood. The advantage of using structural models is that they are able to estimate, in addition to direct structural effects, the indirect effects through other intervening factors. The study also assumes that Saturday travel behavior has an effect on Sunday travel behavior. The subdivided indirect effects of the personal and household attributes on trip generation, activity frequency, and activity durations are empirically analyzed in detail.

가산자료모형을 기초로 한 통행행위의 한계효과분석

장태연 대한교통학회 2003 대한교통학회지 Vol.21 No.3

공분산구조분석법을 활용한 통행수단, 활동 및 통행행태에 대한 인과성 평가

장태연,김대영,김정호,권진영 전북대학교 공학연구원 ( 구 전북대학교 공업기술연구소 ) 2002 工學硏究 Vol.33 No.-

Activities done by individual are usually classified into obligatory and discretionary ones. Simple or complex trip pattern is performed as these activities are linked and various travel modes are used. Individuals try to link several trips as a type of chain to save transportation resources such as travel distance or time, which consequently produces complex trip pattern. These changes in urban transportation environment and less studies on activity-based characteristics make difficult to forecast trips resulting from trip linkage behavior. The purpose of study is to analyze possible causal relationships among activities, travel mode choices and travel patterns, assuming that they are directly influenced by individual or household attributes. Two kinds of models are established to achieve this purpose. One is the allocation model for mode choice for activities by three stage least square estimation method under the restricted conditions. The other is covariance structure model(LISREL) to analyze direct and indirect effect among attributes. As a result, the allocation of travel modes is mainly influenced by variables such as gender, education level, marriage, and children under 13 years old. In LISREL, it is shown that those variables well explain an exogenous personal attributes and only family income do an exogenous household attributes. While trip pattern attributes is well reflected by travel mode attributes, it is less reflected by activity attributes.

[반대] 전주시 경전철 건설

장태연 열린전북 2000 열린전북 Vol.8 No.-

자동차 사회에서의 교통계획

장태연 열린전북 2005 열린전북 Vol.2005 No.7

수요응답형교통(DRT)의 활성화를 위한 중요도-실행도 분석

장태연,김준성 한국ITS학회 2018 한국ITS학회논문지 Vol.17 No.3

농어촌지역에서 수요응답형교통(demand response transport, DRT)이 정착하기 위해서는 수 요부족의 문제가 있는 농어촌버스보다 긍정적 측면이 많아야 된다. 연구는 기존 농어촌버스 와 DRT가 혼용 운행되고 있는 지역에서 DRT의 중요도와 실행도(importance- performance analysis, IPA)를 분석하고, 농어촌버스 만족도와의 관계성 분석하기 위해 IPA의 불일치 이론 을 적용한다. IPA 결과로 가장 시급한 개선항목은 DRT 운행범위이며 환승위치, 환승시간, 환 승거리, 정시도착, 안전운전, 운행시간, 차량수가 개선항목이다. 불일치이론 결과 농어촌버스 와 비교하여 DRT 활성화를 위해서는 실행도보다 중요도가 큰 경우, 환승 편리성, 운행 시간 및 범위, 운행차량에 대해 실행도를 높인다. 실행도보다 중요도가 작은 경우 차량청결도, 안 전운전, 운영자 친절, 환승요소, 운행요소, 요금은 지속적인 실행도가 유지되도록 한다. DRT should have higher positive benefits to become the public transit than the current backcountry buses having demand deficiency and operation problems. The study examines the factors for activating DRT through importance and performance analysis(IPA) and applies the IPA gap theory to find relationship between the current buses and DRT in the mixed operation area. As a result, the operation area is the urgent improving factor and the next ones are transfer related factors, on-time arrival, safe driving, operation time and vehicles. According to the gap theory to activate DRT and reduce the current bus system, in the case that performance is smaller than importance, the performance of transfer, operating time and area, and vehicles should be up. In the case that performance is higher than importance, the performance of luggage space, vehicle clean, safe driving, operator kindness, transfer, operating elements, and fare should keep going.

전주시 경전철이 필요한가?

장태연 열린전북 2001 열린전북 Vol.20 No.-

비신호 교차로에서 횡단 기다림 시간 및 시도횟수에 관한 보행행태 연구

장태연,오도형,Jang, Tae Youn,Oh, Do-Hyoung 대한토목학회 2015 대한토목학회논문집 Vol.35 No.2

본 논문은 무신호 교차로에서 보행자의 횡단행태에 영향을 주는 요소를 분석하였다. 보행행태는 교차로 주변의 환경과 횡단의 기준, 안전에 대한 예견, 순간적인 판단 등이 복합적으로 작용하는 정신적 스트레스의 결과이다. 이러한 복합적 스트레스는 개인의 속성, 교통여건, 환경요인 등 다양한 요인에 의해 영향을 받는데, 이러한 영향요인을 파악하여 교차로를 운영하는데 있어 보행친화적인 환경을 조성할 필요가 있다. 현장과 설문 조사를 통하여 보행자가 비신호 교차로를 횡단하는데 있어서 영향을 주는 다양한 결정변수를 기초로 하여 횡단시도 횟수, 기다림 시간 및 보행횡단 만족도 등에 대한 횡단행태를 분석하는 것이 목적이다. 횡단시도횟수에 대한 각 요소별 특성을 분석하기 위해 $x^2$테스트를 실시하였으며 횡단을 위한 기다림 시간에 영향을 주는 요소를 분석하기 위해 위험률 모형을 구축하였다. 마지막으로 구조방정식을 적용하여 보행자의 보행 횡단 환경에 대한 만족도에 대한 직 간접 효과도 제시되었다. This study analyzes the factors effecting on pedestrian crossing behavior in the unsignalized intersection. Pedestrian crossing behavior is the results of mental stress defined as a combination of environment perception, avoiding accidents, halting collision, and instant crossing decision. It is necessary to make walkable intersection in cities through relieving this stress influenced by personality, traffic condition, and roadway environment. The purpose of study is empirically to examine the crossing behavior such as crossing satisfaction, crossing trial frequency and waiting time based on various factors effecting on crossing intersection by video and questionnaire survey. The $x^2$-test is applied to analyze the characteristics of crossing trial frequency according to each factor. Also, the hazard rate model is established to find the factors effecting on waiting time for crossing. Finally, the direct and indirect effects on the pedestrian crossing satisfaction are presented as the results of LISREL.