• Geomechanics and Engineering
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• 제38권1호
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• pp.1-13
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• 2024

The construction adit plays a pivotal role in enhancing the working face during the excavation of long-distance and deep hydraulic tunnels. However, the intersection zone between the main tunnel and the construction adit exhibits more intricate deformation patterns in surrounding rock, posing a significant threat to stability during excavation. Taking the Xianglushan tunnel in Yunnan Province, China, as a case study, the FLAC3D software is employed to simulate the excavation process at the intersection. The simulation results are verified combined with the field deformation monitoring results, and the spatial distribution of tunnel rock deformation in the intersection area are analyzed. Five excavation conditions with different intersection angles are simulated, and the surrounding rock deformation of the tunnel intersection area with different intersection angles is analyzed, and its influence range is discussed. The results show that: (1) The surrounding rock deformation in the intersection area increases rapidly during the tunnel excavation. With the increase of construction distance, the deformation of intersection area is gradually stable. (2) The deformation distribution of the tunnel rock is uneven, and the deformation of main tunnel near the intersection area is larger than that far away from the intersection area. (3) With the increase of the intersection angle, the surrounding rock deformation of the tunnel intersection and its influence range decreases gradually. The research results have certain guiding significance for the construction safety of the tunnel intersection area.

• 자동차안전학회지
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• 제13권4호
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• pp.106-113
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• 2021

In this study, The behavior of an autonomous vehicle in an intersection accident situation is predicted. Based on a representative intersection accident situation from actual intersection accident database, simulation was performed by applying the automatic emergency braking algorithm used in the autonomous driving system. Accident reconstruction was performed based on the accident report of the representative accident situation. After applying the autonomous driving system to the accident-related vehicle, the tendency of intersection accidents that may occur in autonomous vehicles was identified and analyzed.

• 대한의용생체공학회:의공학회지
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• 제36권3호
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• pp.61-68
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• 2015

In this paper, we studied the effects of intersection angles of the flow-foucusing type droplet generation device inlet channel on droplet diameter using numerical simulation modeling. We modeled different intersection angles with a fixed continuous channel width, dispersed channels width, orifices width, and expansion channels width. Numerical simulations were performed using COMSOL Multiphysics$^{(R)}$ to solve the incompressible Navier-Stokes equations for a two-phase flow in various flow-focusing geometries. Modeling results showed that an increase of the intersection angle causes an increase in the modification of the dispersed flow rate ($v^{\prime}{_d}$), and the increase of the modification of the continuous flow rate ($v^{\prime}{_c}$) obstructs the dispersed phase fluid flow, thereby reducing the droplet diameter. However, the droplet diameter did not decrease, even when the intersection angle increased. The droplet diameter decreased when the intersection angle was less than $90^{\circ}$, increased at an intersection angle of $90^{\circ}$, and decreased when the intersection angle was more than $90^{\circ}$. Furthermore, when the intermediate energy deceased, there was a decrease in the droplet diameter when the intersection angle increased. Therefore, variations in the droplet diameter can be used to change the intersection angle and fluid flow rate.

• 한국ITS학회 논문지
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• 제19권1호
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• pp.83-93
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• 2020

지체시간은 신호교차로의 교통혼잡 수준을 나타내는 주요 지표로 활용되고 있다. 교통정체가 발생하는 대치역사거리와 비교적 교통상황이 원활한 영동5교 사거리를 비교 대상구간으로 선정하여, 현장조사를 기반으로 한 평균지체시간과 다양한 시뮬레이션 프로그램을 통하여 산출한 지체시간을 비교·분석하였다. 현장조사데이터와 신호교차로 분석 모형의 평균 제어지체 비교·분석결과 KHCS는 대치역사거리 7.7초/대, 영동5교사거리 7.9초/대의 차이를 보였으며, VISSIM은 대치역사거리 21.1초/대, 영동5교사거리 8.1초대의 차이로 분석되었다. T7F는 대치역사거리 3.3초/대, 영동5교사거리 9.3초/대의 결과값 차이로 분석되었다. 동일한 교차로를 분석하더라도 시뮬레이션 모형별로 결과값이 차이가 나는 것을 증명하였다.

• 대한기계학회논문집A
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• 제26권9호
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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.

• 자동차안전학회지
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• 제13권4호
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• pp.114-122
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• 2021

In this paper, an automated vehicle intersection collision accident was analyzed through simulation. Recently, the more automated vehicles are distributed, the more accidents related to automated vehicles occur. Accidents may show different trends depending on the sensor characteristics of the automated vehicle and the performance of the accident prevention system. Based on NASS-CDS (National Automotive Sampling System-Crashworthiness Data System) and TAAS (Traffic Accident Analysis System), four scenarios are derived and simulations are performed. Automated vehicles are applied with a virtual system consisting of an autonomous emergency braking system and algorithms that predict the route and avoid collisions. The simulations are conducted by changing the sensor angle, vehicle speed, the range of the sensor and vehicle speed range. A range of variables considered vehicle collision were derived from the simulation.

• 자동차안전학회지
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• 제14권3호
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• pp.35-40
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• 2022

In this study, the driving performances of elderly who's age is over 65 were evaluated. The driving simulation was conducted using a compact driving simulation (CDS) and the simulation scenarios were developed from actual roads by replicating geometry of skewed intersection and traffic control devices located in Jungnang-gu, Seoul, Korea. 27 elderly drivers and 10 non-elderly drivers were recruited and participated on the virtual turning right and going straight driving experiment of CDS. Virtual driving data of driving time, speed, distance, acceleration and deceleration speeds, brake power, and steering wheel rotation angle were recorded and analyzed. Generally, elderly driver took more times to pass through the skewed intersection road and showed lower approaching speed as much as 40% and 25% in case of turning right and going straight scenarios respectively. The speed deviation at skewed intersection road between elderly and non-elderly driver is expected to cause frequent lane changes and overtaking.

• International Journal of Control, Automation, and Systems
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• 제5권2호
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• pp.200-207
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• 2007

The passive direction finding cross localization method is widely adopted in passive tracking, therefore there will exist masses of false intersection points. Eliminating these false intersection points correctly and quickly is a key technique in passive localization. A new method is proposed for passive locating and tracking multi-jammer target in this paper. It not only solves the difficulty of determining the number of targets when masses of false intersection points existing, but also solves the initialization problem of elastic network. Thus this method solves the problem of multi-jammer target correlation and the elimination of static false intersection points. The method which dynamically establishes multiple hypothesis trajectory trees solves the problem of eliminating the remaining false intersection points. Simulation results show that computational burden of the method is lower, the elastic network can more quickly find all or most of the targets and have a more probability of locking the real targets. This method can eliminate more false intersection points.

• 한국CDE학회논문집
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• 제8권4호
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• pp.278-288
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• 2003

Presented in this paper is a numerical method for calculating the intersection points between Z-map vectors and the tool swept surface for circularly moving filleted-end mills. In numerically controlled(NC) machining simulation for large moulds and dies, a workpiece is frequently approximated as a set of z-axis aligned vectors, called Z-map vectors, and then the machining processes can be simulated through updating the Z-map with the intersection points. Circular motions are typically used for machining the free-form surfaces. For fast computation, we express each of intersection points with a single-variable non-linear equation and calculate the candidate interval in which the unique solution exists. Then, we prove the existence of a solution and its uniqueness in this candidate interval. Based on these properties, we can effectively apply numerical methods to finally calculate the solution of the nonlinear equation within a given precision. Experimental results are given for the case of a TV monitor and the hood of a car.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제15권10호
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• pp.3858-3874
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• 2021

As an essential part of the urban transportation system, precise perception of the traffic flow parameters at the traffic signal intersection ensures traffic safety and fully improves the intersection's capacity. Traditional detection methods of road traffic flow parameter can be divided into the micro and the macro. The microscopic detection methods include geomagnetic induction coil technology, aerial detection technology based on the unmanned aerial vehicles (UAV) and camera video detection technology based on the fixed scene. The macroscopic detection methods include floating car data analysis technology. All the above methods have their advantages and disadvantages. Recently, indoor location methods based on wireless signals have attracted wide attention due to their applicability and low cost. This paper extends the wireless signal indoor location method to the outdoor intersection scene for traffic flow parameter estimation. In this paper, the detection scene is constructed at the intersection based on the received signal strength indication (RSSI) ranging technology extracted from the wireless signal. We extracted the RSSI data from the wireless signals sent to the road side unit (RSU) by the vehicle nodes, calibrated the RSSI ranging model, and finally obtained the traffic flow parameters of the intersection entrance road. We measured the average speed of traffic flow through multiple simulation experiments, the trajectory of traffic flow, and the spatiotemporal map at a single intersection inlet. Finally, we obtained the queue length of the inlet lane at the intersection. The simulation results of the experiment show that the RSSI ranging positioning method based on wireless signals can accurately estimate the traffic flow parameters at the intersection, which also provides a foundation for accurately estimating the traffic flow state in the future era of the Internet of Vehicles.