• International Journal of Highway Engineering
• /
• v.16 no.1
• /
• pp.91-98
• /
• 2014

PURPOSES : Recently, there are increasing bicycle accidents along with increasing bicycles users. Bicycle accidents occurred frequently by perpendicular collision form at intersection inner. In order to improve safety of bicycle, drivers need to be aware of bicycles on the road and intersection geometric designs need to be designed to reduce risk associated with collisions between bicycles and car. This study aims to review the location of bicycle crossing in the viewpoint of bicycle safety. METHODS : Four types of bicycle crossing by curve radius and driver's check around the behavior are set to simulate the risk of collisions between bicycles and car turning right. Simulation using fortran programming are conducted on total 60 cases. RESULTS : Bicycle crossing located behind of crosswalk is lower the risk of collisions with car in all cases. In addition to the larger curve radius of pavement edge at intersection and the more pay attention to the rear by the turn head to the right is too low the risk of collisions with car. CONCLUSIONS : It is show that the location of bicycle crossing is safer behind than in front of crosswalk in the viewpoint of bicycle safety.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.10 no.10
• /
• pp.4825-4847
• /
• 2016

In this paper, we focus on the per-flow throughput analysis of IEEE 802.11 multi-hop ad hoc networks. The importance of an accurate saturation throughput model lies in establishing the theoretical foundation for effective protocol performance improvements. We argue that the challenge in modeling the per-flow throughput in IEEE 802.11 multi-hop ad hoc networks lies in the analysis of the freezing process and probability of collisions. We first classify collisions occurring in the whole transmission process into instantaneous collisions and persistent collisions. Then we present a four-dimensional Markov chain model based on the notion of the fixed length channel slot to model the Binary Exponential Backoff (BEB) algorithm performed by a tagged node. We further adopt a continuous time Markov model to analyze the freezing process. Through an iterative way, we derive the per-flow throughput of the network. Finally, we validate the accuracy of our model by comparing the analytical results with that obtained by simulations.

• Journal of Navigation and Port Research
• /
• v.46 no.2
• /
• pp.99-109
• /
• 2022

A report released by the Chinese Maritime Court found that the natural environment and other objective factors have greatly reduced the risk of ship collision accidents with the advancement of technologies. However, collisions between merchant ships and fishing boats occur frequently along the coast during fishing seasons, which should be highly valued. International conventions and domestic legislation in China comprise detailed laws with respect to ship collisions, but the theory of ship collision infringement needs to be improved, enriched, and developed. Meanwhile, the development of the tort liability law provides theoretical support for ship collision infringement. As far as China's ship tort legal system is concerned, the research on ship collision tort damage compensation is relatively extensive, and the constitutive elements and causality of ship collision tort liability have also been studied in depth. The purpose of this paper is to explore the domestic legislation applicable to disputes related to ship collisions in China. As these laws are unclear on the resolution of disputes resulting from ship collisions, significant attention has been focused on the final judgments by the Supreme Court of China (SPC), as well as the judicial judgments set by the Maritime Court of China.

• Journal of the Korean Society of Fisheries and Ocean Technology
• /
• v.50 no.3
• /
• pp.252-261
• /
• 2014

Marine casualties originated from fishing vessel occupied about 70% of the whole marine casualties in Korea from 2001 to 2010, this ratio was not much changed as it was before. Therefore a pragmatic counterplan to decrease of casualties in fishing vessel is indispensable for reduction of the nationwide marine casualties. But since the casualties occurred by fishing vessel may have a different causes and counterplan according to the operating type of it, in this paper, fishing vessels classified into 12 types by operating method and inspected the causes and counterplan for that. The operating type of fishing vessel occurred the specific casualties more were jig boat in collisions and fire explosion, trap fishing boat, mixed fishing boats and inshore gill netter in collisions, stow netter in machinery damages and capsizing, offshore gill netter in machinery damages, fish carrier in collisions. It must be emphasized that the higher ranked types of vessels, especially jig boat have to take special care to the approaching vessels under way, trap fishing boat to rear look out and mixed fishing boat must keep on safety speed and be taken an education for advance the skill of operating radar as well. For all 12 types of fishing vessel, it is necessary for an operator to make strict precaution on the other vessel under way systematically and keep the regulation for preventing collisions, and for an engineer on watch to make a check the electricity and the engines periodically for reduction the fire explosion and machinery damages.

• Journal of Auto-vehicle Safety Association
• /
• v.3 no.2
• /
• pp.34-41
• /
• 2011

Side collisions (or side crash) account for 51.6% of all car to car accidents occurred in 2010. It is necessary to analyze those vehicles' structure deformation and passengers' injuries in the side collisions. A moving barrier (950kg) is currently used in the KNCAP side impact test. However, in order to enhance a passengers' safety in the side collisions, we introduce an AE-MDB (1500kg) which provides more severe conditions for this test. In this study, the test results using both barriers are compared and analyzed.

• Journal of the Korean Vacuum Society
• /
• v.10 no.3
• /
• pp.283-288
• /
• 2001

We have investigated aluminum cluster deposition using a classical molecular dynamics simulations. We studied the variations of the cluster momentum and the impulse force during collisions, and found that the close-packed cluster impact has some of properties of the single particle collision and the linear atomic chain collisions. We also simulated the series of energetic cluster deposition with energy Per atom. When energy Per atom in cluster has some eV rather than very low, the intermixing occurred easily in growth film and we can obtain a good film without subsequent annealing process.

• Journal of the Korean earth science society
• /
• v.22 no.5
• /
• pp.423-426
• /
• 2001

The accretion disk with viscosity including collisions is examined. The diffusion process are also considered for a given mass distribution in the disk. Under such a circumstance the diffusion coefficient is simply proportional to 1/${\sqrt{r}}$ The disk rapidly transfers the turbulent angular momentum and the wave front toward the outer cold regions. Then an instability situation occurs in the disk.

• Journal of KIISE:Computer Systems and Theory
• /
• v.35 no.1
• /
• pp.44-52
• /
• 2008

In this paper we consider detecting collisions between characters whose motion is specified by motion capture data. Since we are targeting on massive crowd simulation, we only consider rough collisions, modeling the characters as a disk in the floor plane. To provide efficient collision detection, we introduce a hierarchical bounding volume, the Motion Oriented Bounding Box tree (MOBB tree). A MOBBtree stores space-time bounds of a motion clip. In crowd animation tests, MOBB trees performance improvements ranging between two and an order of magnitude.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2003.06a
• /
• pp.321-324
• /
• 2003

There are two steps to solve the self-collision avoidance problems for redundant manipulators. First, all links are regarded as cylinders. and then the collisions should be checked among all pairs of the links. Between two cylinders. we can get the collision information derived from the concept or configuration space obstacle in real time. Therefore. it is possible to detect the links where collisions are likely in real time by setting the risk radius which is larger than actual radius. Second. the configuration control points (CCP) should be placed at the ends of the detected links. A cost function is the sum of the distances between the CCPs. To maximize the cost function means the links go far away each other without self-collisions.

• Proceedings of the IEEK Conference
• /
• 1999.06a
• /
• pp.1113-1116
• /
• 1999

For mobile robot, the navigation effectiveness can be improved by providing autonomy, but this autonomy requires the mobile robot to detect unknown obstacles and avoid collisions while moving it toward the target. This paper presents an effective method for autonomous navigation of the mobile robot in structured environments. This method uses ultrasonic sensor array to detect obstacles and utilizes force relationship between the obstacles and the target for avoiding collisions. Accuracy of sensory data produced by ultrasonic sensors is improved by employing error eliminating rapid ultrasonic firing (EERUF) technique. Navigation algorithm controlling both the velocity and steering simultaneously is developed, implemented to the mobile robot and tested on the floor filled with the cluttered obstacles. It is verified that from the results of the field tests the mobile robot can move at a maximum speed of 0.66 m/sec without any collisions.