Lane-following method for high speed autonomous vehicles

This paper presents a steering control method for lane-following in a vehicle using an image sensor. With each image frame acquired from the sensor, the steering control method determines target position and direction, and constructs a travel path from the current position to the target position either as an Arc-path or S-path. The steering angle is calculated from the travel path thus generated, and the vehicle follows the travel path via motor-control. The method was tested using a vehicle dubbed as KAV (Korea Autonomous Vehicle) along an expressway (Seoul Inner Beltway) trajectory with a variety of radii (50 m ∼ 300 m) while traveling at a speed of 60 km/h to 80 km/h. Compared with an experienced human driver, the method showed little much difference in performance in terms of lane-center deviation. The proposed method is currently employed for high speed autonomous driving as well as for stop and go traffic.     

Conditional modelling of tanker market risk using route specific freight rates

This paper provides statistical evidence in support of the view, widely held in the tanker industry, that there are systematic differences in the degree of risk involved in investing in tankers of different sizes, and in operating tankers in spot and time charter markets. The industry view, broadly supported by the results of this paper, is that larger vessels are 'risker' assets than smaller vessels, and operating vessels in the time-charter market is less risky than employing them on a spot basis. The results are obtained by using a method derived from the financial economics literature, which models both the conditional mean and variance of a variable, known as GARCH modelling. Only one other paper has applied this method to the tanker market, and these results provide confirmatory support of those findings.     

考虑疲劳强度和减轻质量的转向架构架设计

用有限元法对各种载荷工况下的转向架构架进行了疲劳分析,利用人工神经网络和遗传算法最大程度地减轻了转向架构架的质量.     

Managing passenger behavioral intention: an integrated framework for service quality,satisfaction, perceived value,and switching barriers

This paper seeks to improve our understanding of passengers’ behavioral intention by proposing an integrated framework from the attitudinal perspective. According to the literature in marketing research, we establish a causal relationship model that considers “service quality-satisfaction-behavioral intentions” paradigm, perceived value theory, and switching barrier theory. Exploring passengers’ behavioral intention from satisfaction and perceived value help to understand how passengers are attracted by the company, while switching barriers assist in realizing how passengers are “locked” into a relationship with the current company. Furthermore, in order to capture the nature of service quality, we adopt a hierarchical factor structure which serves service quality as the higher-order factor. In this study, coach industry is selected as our research subject. The empirical results, as hypothesized, show that all causal relationships are statistically significant, and perceived value us the most important predictor of satisfaction and passengers’ behavioral intention. In conclusion, the managerial implications and suggestions for future research are discussed.     

Numerical simulation on truncated oval-nosed projectile penetrating into stiffened plate北大核心CSCD

[Objectives]In this paper, the numerical simulation method is used to study the anti-penetration performance and energy absorption mode of a stiffened plate, as well as the influence of different stiffened bars on the flight attitude of the projectile body.[Methods] Finite element software LS-DYNA is used to simulate the process of a truncated oval-nosed projectile penetrating a stiffened plate, and the results of the numerical simulation are compared with an experiment to verify the reliability of the numerical simulation method. The momentum method and mass equivalence method are used to predict the residual velocity of the projectile, and the applicability of different theoretical methods within different velocity ranges is compared. The deformation energy of different regions of the stiffened plate is then extracted to analyze the influence of the initial velocity of the projectile body on the energy absorption mode of the target plate. Finally, the structure of the stiffeners is changed and the influence of the relative position of the stiffeners on the penetration attitude of the projectile body is analyzed.[Results]The results show that the mass equivalence method is more accurate than the momentum method in predicting the residual velocity of the stiffened plate when the initial velocity of the projectile body is in the range of 300–900 m/s. The ratio of the deformation energy of the stiffened plate to the energy loss of the projectile body decreases with the increase of the initial velocity of the projectile body. The effect of a T-stiffened plate on trajectory is greater than that of a rectangular-stiffened plate.[Conclusions]The related calculation method and research results have certain reference value for research and engineering application surrounding the anti-penetration of stiffened plates. © 2023 Chinese Journal of Ship Research. All rights reserved.     

A Novel Image Encryption Technique Based on Inter Block Difference

Data security plays a vital role in the current scenario due to the advanced and sophisticated data access techniques.Present development in data access is alwa...     

Design and implementation of a UPnP-can gateway for automotive environments

In this paper, we propose a universal plug and play (UPnP) — controller area network (CAN) gateway system using UPnP middleware for interoperability between external smart devices and an in-vehicle network. The proposed gateway consists of a UPnP communication device, a CAN communication device, and a device translator layer. In-vehicle devices are not usually IP-based, so we implemented an in-vehicle device manager in the UPnP communication device which is in the gateway. We developed a vehicle simulator to produce real vehicular data for performance analysis. The CAN communication device transmits and receives real-time vehicle data between the real vehicular simulator and external devices through the UPnP. The device translator layer configures a message frame for enabling seamless data input and output between the CAN and UPnP protocols. After implementation, we generated an internal-external service request and tested the result. Finally, we confirmed the service request and operation between external devices and the internal vehicular device. Additionally, for a variety of external device numbers and communication environments, we demonstrated the gateway performance by measuring the round trip time (RTT) for overall service implementation.     

Biological Status Assessment of Coral Reefs in Southern Puerto Rico: Supporting Coral Reef Protection Under the U.S. Clean Water Act

Abstract

States and other jurisdictions may protect coral reefs using biological water quality standards outlined by the United States Clean Water Act (CWA). Such protection will require long-term, regional monitoring of the resource using biological indicators and a probability-based sampling design. A 60-station survey targeting nearshore linear coral reef was conducted across southern Puerto Rico in December 2011 to document the status of reef inhabitants using a probabilistic, regional sampling design. The quantity, type and condition of stony corals, fish, gorgonians, and sponges were documented from each station, providing a robust representation of linear reef status and composition across the region. Fish represented 106 unique taxa and stony corals 32 unique taxa. Benthic organisms (stony corals, sponges, and gorgonians) averaged nearly 12 colonies per square meter, more than half of which were gorgonians. Assessment results can be used as a baseline to compare with future regional surveys to quantify change in reef condition over time (trend). Both temporal and spatial changes can be expected after large-scale disturbances like hurricanes Maria and Irma in 2017. The indicators and probabilistic sampling design support the long-term regional monitoring envisioned by the Environmental Protection Agency to implement CWA protections in Puerto Rico and elsewhere.