• Asian-Australasian Journal of Animal Sciences
• /
• v.2 no.3
• /
• pp.366-367
• /
• 1989

• Journal of Korean Society of Transportation
• /
• v.25 no.3
• /
• pp.111-121
• /
• 2007

A transit assignment model can forecast the behaviors of transit users. thereby playing an important role In the evaluation of transit policies. Most existing transit assignment models are based on the models for passenger cars; therefore they cannot reflect the specific characteristics of transit modes. In addition most of the existing models are based on a single transit mode (bus or rail), and they cannot forecast the behaviors of transit users in a changing mass transportation system. The goal of this study is to overcome these problems with the exiting models and to develop a more realistic model. The newly developed model is based on mixed transit modes and is a stochastic model that can reflect the different preferences of each transit user for travel time and transfering. Data gathered from the Seoul metropolitan area's smart card are used to calibrate this model. This study is expected to be used for the evaluation of transportation policies and to attribute the development of transit revitalization strategies.

• Journal of the Institute of Electronics Engineers of Korea SD
• /
• v.39 no.3
• /
• pp.41-48
• /
• 2002

The bandwidth limitation of traveling-wave electroabsorption modulator(TW-EAM) is determined by the transit time, the velocity-mismatch between optical-wave and microwave, the impedance-matching, the dispersion and the microwave loss. In this paper, we introduce an hovel impulse response of TW-EAM considering transit time as well as velocity-mismatch. We analyze the effect of transit-time and velocity-mismatch at the same time, using the FDTD method. We investigate the modulation bandwidth by changing the depth of the intrinsic region. We suggest that the optimum depth of the intrinsic region is 0.2${\mu}{\textrm}{m}$ when the absorption coefficient($\alpha$) is 0.2${\mu}{\textrm}{m}$-1.

• The Korean Journal of Nuclear Medicine
• /
• v.22 no.2
• /
• pp.199-203
• /
• 1988

The authors observed functional change of the CBD and the afferent loop with the transit time of $^{99m}Tc-DISIDA$ scintigram in patients treated by the surgical operation of gastric ulcers and cancer at Busan National University Hospital from June, 1987 to April, 1988. So authors estimated the time between the peak activity of the CBD and the afferent loop (TCA), the half transit time of the CBD activity (t 1/2 CBD) and the half transit time of the afferent loop activity (t 1/2 A-loop) in 9 patients undergone truncal vagotomy, who have no specific symptoms at 2 to 6 months after the operation, 5 patients undergone the operation without truncal vagotomy, and 7 persons as a control group. The results were as follows: I) In control group, the mean TCA, t 1/2 CBD and t 1/2 duodenum were $8.6{\pm}9.0$ min, $38.7{\pm}17.3$ min. and $28.6{\pm}10.9$ min, respectively. 2) In the operation group without truncal vagotomy, the mean TCA, t 1/2 CBD and t 1/2 A-loop were $10.0{\pm}7.1$ min. $48.2{\pm}22.3$ min. and $39.4{\pm}26.7$ min. respectively. 3) In the operation group with truncal vagotomy, the mean TCA, t 1/2 CBD and t 1/2 A-loop were $15.0{\pm}8.7$ min., $36.1{\pm}16.5$ min. and $42.6{\pm}24.4$ min, respectively. From the above results, we concluded that the transit time of the CBD and the afferent loop is not affected by truncal vagotomy.

• Proceedings of the KSR Conference
• /
• 2010.06a
• /
• pp.1409-1415
• /
• 2010

A linear induction motor have advantages for reducing mechanical frictions and noises because it has thrust force by induced torque instead of friction force between rail and wheels. An it has additional advantage for reducing volume of bogie frame for light rail transit. The small volume causes the cost of construction down. Recently, researches of linear induction motor for thrust force of the light rail transit have been actively studied. For the rail transit, vehicle is running as follow accelerating and constant speed, finally decelerating speed passing local stops between stations. The light rail transit have only these three patterns of operating. Thus, design of that has different design specifications from others. In this paper, the linear induction motor for the light rail transit was designed considering the goal speed, accelerating time, and accelerating distance for approaching the goal speed. The designed motor was proved that it could meet the requirement of accelerating performance by2-dimensional finite element method and mechanical dynamics equation.

• Proceedings of the KIEE Conference
• /
• 2007.10c
• /
• pp.229-231
• /
• 2007

The CCTV, closed circuit television, system is the most popular method to monitor some specific area. The CCTV-based monitoring system is composed of a lot of cameras installed the areas, and monitors to display the vision through the cameras. However, these systems have limitations to prevent some problems or to cope with the problems promptly, because they can carry out only the function that shows us the analogue images of the cameras. Especially, urban transit service area is the space where many people crowd in all at the same time and the space is not only wide but also distributed sporadically. This paper presents the efficient plan for video-based monitoring system to monitor urban transit service area. To build the efficient monitoring system, it is necessary to devide the monitoring area to appropriate sectors that should be composed to be displayed at a time. If the proposed method is used to construct the video-based monitoring system, the operating officers in the urban transit have the more direct and real images.

• Journal of the Korean Society of Safety
• /
• v.27 no.6
• /
• pp.31-42
• /
• 2012

Urban transit vehicle that uses electrical energy, is faster, safer and energy-efficient public transit than other means. As a Research method, the Matlab/Simulink are used to modeling a regenerative brake-capable train, and actual parameters such as powering and braking characteristics, all kinds of resistance, passenger load, velocity, gradient, radius of curve etc and powering and breaking commands per time or distance are inputted to train's dynamic equation, then a simulation program is made and used to yield train driving pattern and driving time and the amount of driving energy used thereby at auto and manual operation and at all sector.

• Journal of Biomedical Engineering Research
• /
• v.27 no.3
• /
• pp.89-93
• /
• 2006

A simple algorithm that can be used to estimate a healthy person's blood pressure using pulse transit time is proposed in this paper. Fifty healthy students participated in the experiment that was conducted in line with the study. The subjects were asked to exercise on several exercise levels using a bicycle ergometer. Their blood pressures during the succeeding rest period were measured. A simple method was proposed to illustrate the relationship between blood pressure and pulse transit time. The systolic blood pressures as well as the heights and weights of the subjects were regarded as the proper parameters, and a second-order regression curve was produced to estimate the subjects' blood pressures. The mean error of estimation was less than 10 mmHg, which was the mean error of manual measurement. Although our estimation model is so simple, it can be used to estimate continuous blood pressure measurement for bicycle ergometer exercise. The electrocardiograms, photoplethysmograms, and blood pressures, however, could not be measured simultaneously As such, their estimation may be slightly different from the results taken from simultaneous measurements.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.64 no.11
• /
• pp.1578-1586
• /
• 2015

Personal rapid transit (PRT) is getting attention as a new form of transportation. It is energy efficient and provides the high level of passenger service. In this study, the dynamic PRT dispatching and routing problem is dealt with. Passengers request transportation service on a complex network, and an operating system monitors passenger arrivals and coordinates vehicles in real time. A new online dispatching and routing algorithm is proposed, which minimizes the total travel distance of vehicles and the waiting time of passengers. The algorithm dispatches vehicles by considering multiple vehicles' state and multiple passengers at the same time. In particular, finding the shortest-time path is attempted by taking into account the future congestion on lanes. Discrete-event simulation is employed to validate the performance of the proposed algorithm. The results show the algorithm in this study outperforms others.

• Journal of Korean Society of Transportation
• /
• v.25 no.3
• /
• pp.145-154
• /
• 2007

Determining stop spacing is a very important process in transit system planning. This study is involved in an analytical approach to decide the transit stop spacing. Transit stop spacing should be longer as 1) user access speed, 2) user travel time, and 3) dwell time increase, and shorter as 1) passengers (boardings and alightings) and 2) headway increase. In this study, a methodology is proposed to determine transit stop spacing to minimize total cost (user cost plus operator cost) with irregular passenger distribution (boardings and alightings) Without considering in-vehicle passengers, the transit stop spacing should be shorter in the concentrated sections of the passenger distribution than in others to minimize total cost. Through the conceptual analysis, it is verified that the transit stop spacing could be longer as the in-vehicle passengers increase in certain sections. This study proposes a simple practical method to determine transit stop spacing and locations instead of a dynamic programming method which generally includes a complex and difficult calculation. If the space axis is changed to a time axis. the methodology of this study could be expanded to analyze a solution for the transit service (or headway) schedule problem.