• Journal of Korean Society of Transportation
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• v.17 no.5
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• pp.79-86
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• 1999

Traffic jams of our country are due to the shortage of roadway as compared with the traffic, however. they are sometimes due to inconsistency of the roadway capacity. Inconsistency of the roadway capacity comes from the difference of cycle length, phase length and number of Phase between major intersection and minor intersection. Specialty increasing number of Phase due to left-turn movements bring out decrease of the arterial capacity, deterioration of the arterial offset. The Purpose of this research is to introduce and analyze the continuous flow intersection to solve the bottleneck of the major intersection. The major contents of this research introduce the concept and design consideration for the continuous flow intersection and also analyze delay, fuel consumption and emissions among multiphase intersection, grade separated intersection and continuous flow intersection. This research analyze the sensitivities according to change of the left-turn traffic volume and also evaluate the cost-effectiveness through the total cost analysis among three of them.

• Proceedings of the KOR-KST Conference
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• 1996.02a
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• pp.59-86
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• 1996

Current methods for evaluating unsignalized intersections, and estimating level-of-service (LOS) is determined from efficiency-based criteria such as little or no delay to very long delays. At present, similar procedures to evaluate intersections using safety-based criteria do not exist. The improvement of sight distances at intersections is the most effective way of improving intersection safety. However, a set of procedures is necessary to account for the limitations in current methodology. Such an approach would build upon such methods, but also account for: deficiencies in the current deterministic solution for the determination of intersection sight distances; opportunity for an accident and severity of an accident; and cost-effectiveness of attaining various levels of sight distances. In this research, a model that estimates the degree of safety at two-way stop-controlled intersections is described. Only crossing maneuvers are considered in this study because accidents caused by the crossing maneuvers are the dominate type among intersection accidents. Monte Carlo methods are used to estimate the hazard at an intersection as a function of roadway features and traffic conditions. Driver`s minimum gap acceptance in the crossing vehicles and headway distribution on the major road are used in the crossing vehicles and headway distribution on the major road are used in the model to simulate the real intersectional maneuvers. Other random variables addressed in the model are: traffic speeds; preception-reaction times of both drivers in the crossing vehicles and drivers in oncoming vehicles on the major road; and vehicles on the major roads. The developed model produces the total number of conflicts per year per vehicle and total potential kinetic energy per year per vehicle dissipated during conflicts as measurements of safety at intersections. Based on the results from the developed simulation model, desirable sight distances for various speeds were determined as 350 feet, 450 feet and 550 feet for 40 mph, 50 mph and 60 mph prevailing speed on the major road, respectively. These values are seven to eight percent less than those values recommended by AASHTO. A safety based level-of-service (LOS) is also developed using the results of the simulation model. When the total number of conflicts per vehicle is less than 0.05 at an intersection, the LOS of the intersection is `A' and when the total number of conflicts per vehicle is larger than 0.25 at an intersection, the LOS is `F'. Similarly, when the total hazard per vehicle is less than 350, 000 1b-ft2/sec2, the LOS is `F'. Once evaluation of the current safety at the intersection is complete, a sensitivity analysis can be done by changing one or more input parameters. This will estimate the benefit in terms of time and budget of hazard reduction based upon improving geometric and traffic characteristics at the intersection. This method will also enable traffic engineers in local governments to generate a priority list of intersection improvement projects.

• International Journal of Highway Engineering
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• v.10 no.3
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• pp.47-56
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• 2008

Generally, accident exposure at intersections is relatively higher than that at roadway segments due to more possibility of merging, diverging, turning, crossing, and weaving maneuver. Furthermore, the traffic accident rate at intersections has been rapidly increasing since 1990's. Since there is more opportunity of conflict at unsignalized intersection, frequency and severity of traffic accident are more severe than signalized intersections. The purpose of the study is to analyze factors causing vehicle crashes and provide intersection design guidelines to improve intersection safety. For this study, vehicle to vehicle crash data of 116 rural 3 legs unsignalized were collected and field surveys were conducted for traffic and geometric conditions. Ordered probit models were developed to analyze the severity of crashes. It was found that weather, obstacles in minor roadsides, presence of major exclusive right lane, presence of major road crosswalk, difference between posted speed of major road and minor road, land-use around intersections, shoulder width of major road, ADT of major road are significant factors for intersection safety.

• Proceedings of the KSME Conference
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• 2001.06c
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• pp.235-239
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• 2001

Finding intersection point between a surface and a line is one of major problem in CAD/CAM. The intersection point could be found in an exact form or with numerical method. In this paper, the exact solution of the intersection point between a ruled surface which is generated by the movement of an endmill and the z-direction vector is presented. The cutter swept surface which is a ruled surface and the Z-direction vector are represented with parametric equations. With the nature of parametric equations, the geometric properties at the intersection point are easily acquired.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.19 no.1
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• pp.83-93
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• 2020

The time delay is used as a major indicator of the level of traffic congestion on traffic crossroads. For this purpose, the Daechi Station intersection where traffic congestion occurs and the Yeongdong 5 Bridge intersection where the traffic condition is relatively good, and the average lag time based on the field survey with the lag time calculated various simulation programs. comparison of the average control delay of the field survey data the signal intersection analysis model the KHCS Dechi intersection 7.7 second / vehicle Young dong 5 bridge intersection 7.9 second / vehiclehe VISSIM showed a difference Dechi intersection 21.1 second / vehicle and Young dong 5 bridge intersection 8.1 second / vehiclehe T7F showed a difference Dechi intersection 3.3 second / vehicle and Young dong 5 bridge intersection 9.3 second / vehicle. Analyzing the same intersection proved that the results differed from one simulation model to another.

• International Journal of Highway Engineering
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• v.12 no.2
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• pp.1-7
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• 2010

This study deals with the unsignalized intersection delay in the urban transportation demand forecasting. The objectives are to develop the unsignalized intersection delay models and to comparatively analyze the applicability of the above models. In pursuing the above, this study gives particular attentions to simulating by KHCS program and implementing the case study of Cheongju using EMME/2. The major findings are the followings. First, the 8 unsignalized intersection delay models were developed through 480 simulating results, which are all statistically significant. Second, the estimates by the unsignalized delay models were analyzed to be most fitted to the observed traffic volume data.

• The Journal of the Acoustical Society of Korea
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• v.19 no.2E
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• pp.27-31
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• 2000

Evaluating log-likelihood of Gaussian mixture density is major computational burden for the keyword spotting system using continuous HMM. In this paper, we employ the bucket box intersection (BBI) algorithm to reduce the computational complexity of keyword spotting. We make some modification in implementing BBI algorithm in order to increase the discrimination ability among the keyword models. According to our keyword spotting experiments, the modified BBI algorithm reduces 50% of log-likelihood computations without performance degradation, while the original BBI algorithm under the same condition reduces only 30% of log-likelihood computations.

• Proceedings of the KSRS Conference
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• 2003.11a
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• pp.606-608
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• 2003

This paper investigates the accuracy of three-dimensional positioning for EROS A stereo pairs when different numbers of ground control points are employed. The major works of the proposed schemes include: (1) initialization of orientation parameters (2) preliminary orbit fitting, (3) orbit refinement using the least squares filtering technique, and (4) space intersection. The experiment includes validation of positioning accuracy for an EROS A in-track stereo pair when different number of check points are employed.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.26 no.9
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• pp.1814-1821
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• 2002

NC cutting simulation is an important factor in the development of products. The geometric modelling of cutter swept surface should be done in NC cutting simulation. A part of cutter swept surface is a ruled surface blended with silhouette curve and cutter path. Finding an intersection point between cutter swept surface and a line is one of major problems in Z-map based cutting simulation. In this paper, cutter swept surface is defined parametrically and it's intersection point with Z-map is found in an exact form. Triangular grid Z-map based 3-axis NC cutting simulation is performed.

• MALSORI
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• no.60
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• pp.109-123
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• 2006

Since computing the log-likelihood of Gaussian mixture density is a major computational burden for the speech recognizer based on the continuous HMM, several techniques have been proposed to reduce the number of mixtures to be used for recognition. In this paper, we propose a modified Bucket Box Intersection (BBI) algorithm, in which two relative thresholds are employed: one is the relative threshold in the conventional BBI algorithm and the other is used to reduce the number of the Gaussian boxes which are intersected by the hyperplanes at the boxes' edges. The experimental results show that the proposed algorithm reduces the number of Gaussian mixtures by 12.92% during the recognition phase with negligible performance degradation compared to the conventional BBI algorithm.