420 research outputs found
Incorporation of biomechanical child cadaver neck behaviour in a child model and injury prediction in vehicle frontal crash
This research was completed in an effort to improve the biofidelity of a finite element child model and the accuracy of injury predictions in forward facing child restraint seats during numerical simulations of frontal crashes.
After material alterations to the child model, neck tensile force was found to be within the range of cadaver tests and the rotation-moment curves were in good agreement with the corridor of the pediatric cadaver head/neck complex tests.
The altered child model has illustrated more accurate biomechanical responses and kinematics; its biofidelity has been improved. The upper and lower neck tensile forces of the child model were reduced by approximately 35% and 41%, respectively. Tensile deformation of the child neck was increased by 2.75 times while rotational deformation increased by 37%. The percentage error of the maximum displacements of the child head was reduced from approximately 16% to 13.5%
Can Alternative Investments Benefit Diversification?
The present study is designed to empirically test portfolio diversification benefits in alternative investments, such as private equity, venture capital, hedge funds, real assets, and private placement debt. This paper seeks to horizontally evaluate the risk performance in mixed portfolios consisting of traditional and alternative investments for a given level of return. We assess the individual of diversification benefits by decomposing traditional and alternative risk measures in optimal portfolios. Using quarterly data from Preqin, Liv-Ex, Eurekahedge, and Artprice database, this article investigates a comprehensive picture in alternative and traditional investments statistically. By analyzing the empirical result from alternative risk measures, we validate diversification benefits from alternative investments. We find that a portfolio with alternative assets tends to have a lower risk for a given level of return than the benchmark portfolio only consisting of stocks and bonds. Furthermore, incorporating alternative assets, such as hedge funds, private equity, and private placement debt, into traditional portfolios improves the benefits of diversification. Several assets, however, may not help investors improve the benefits, like the artwork investment and natural resources.Bachelor of Scienc
Urban rail transit passenger service quality evaluation based on the KANO–Entropy–TOPSIS model: the China case
In order to evaluate the URTPSQ (Urban Rail Transit Passenger Service Quality) comprehensively, find the shortage of URTPSQ, find out the difference between the actual service situation and the passenger’s expectation and demand,and provide passengers with better travel services, a passenger-oriented KANO–Entropy–TOPSIS (Technique for Order of Preference by Similarity to Ideal Solution) method is proposed and applied in this paper. Firstly, a KANO model is applied to select the service quality indicators from the 24 URTPSQ evaluation sub-indicators, according to the selection results, the KANO service quality indicators of URTPSQ are constructed. Then the sensitivity of the KANO service quality indicators based on the KANO model are calculated and ranked, the PS (Passenger Satisfaction) of each KANO service quality indicator by using the Entropy–TOPSIS method is calculated and ranked. Based on the difference between the sensitivity degree rank and the satisfaction degree rank of each KANO service quality indicator, determine the service quality KANO indicators of the URTPSQ that need to be improved significantly. A case study is conducted by taking the Chengdu subway system in China as a background. The results show that the Chengdu subway operation enterprises should pay attention to the must-be demand first, then the one-dimensional demand, finally the attractive demand. The three indicators, including transfer on the same floor in the station, service quality of staffs of urban rail transit enterprises,and cleanness in the station and passenger coach, need to be improved urgently. For the managers and operators of urban rail transit system, the passengers’ must-be demand should be satisfied first if the KANO model is applied to evaluate the service. The indicators with highest sensitivity degree and lowest TOPSIS value should be improved based on the KANO–Entropy–TOPSIS model.
First published online 14 December 202
Integration of biometrics and steganography: A comprehensive review
The use of an individual’s biometric characteristics to advance authentication and verification technology beyond the current dependence on passwords has been the subject of extensive research for some time. Since such physical characteristics cannot be hidden from the public eye, the security of digitised biometric data becomes paramount to avoid the risk of substitution or replay attacks. Biometric systems have readily embraced cryptography to encrypt the data extracted from the scanning of anatomical features. Significant amounts of research have also gone into the integration of biometrics with steganography to add a layer to the defence-in-depth security model, and this has the potential to augment both access control parameters and the secure transmission of sensitive biometric data. However, despite these efforts, the amalgamation of biometric and steganographic methods has failed to transition from the research lab into real-world applications. In light of this review of both academic and industry literature, we suggest that future research should focus on identifying an acceptable level steganographic embedding for biometric applications, securing exchange of steganography keys, identifying and address legal implications, and developing industry standards
Security and accuracy of fingerprint-based biometrics: A review
Biometric systems are increasingly replacing traditional password- and token-based authentication systems. Security and recognition accuracy are the two most important aspects to consider in designing a biometric system. In this paper, a comprehensive review is presented to shed light on the latest developments in the study of fingerprint-based biometrics covering these two aspects with a view to improving system security and recognition accuracy. Based on a thorough analysis and discussion, limitations of existing research work are outlined and suggestions for future work are provided. It is shown in the paper that researchers continue to face challenges in tackling the two most critical attacks to biometric systems, namely, attacks to the user interface and template databases. How to design proper countermeasures to thwart these attacks, thereby providing strong security and yet at the same time maintaining high recognition accuracy, is a hot research topic currently, as well as in the foreseeable future. Moreover, recognition accuracy under non-ideal conditions is more likely to be unsatisfactory and thus needs particular attention in biometric system design. Related challenges and current research trends are also outlined in this paper
Security and accuracy of fingerprint-based biometrics: A review
Biometric systems are increasingly replacing traditional password- and token-based authentication systems. Security and recognition accuracy are the two most important aspects to consider in designing a biometric system. In this paper, a comprehensive review is presented to shed light on the latest developments in the study of fingerprint-based biometrics covering these two aspects with a view to improving system security and recognition accuracy. Based on a thorough analysis and discussion, limitations of existing research work are outlined and suggestions for future work are provided. It is shown in the paper that researchers continue to face challenges in tackling the two most critical attacks to biometric systems, namely, attacks to the user interface and template databases. How to design proper countermeasures to thwart these attacks, thereby providing strong security and yet at the same time maintaining high recognition accuracy, is a hot research topic currently, as well as in the foreseeable future. Moreover, recognition accuracy under non-ideal conditions is more likely to be unsatisfactory and thus needs particular attention in biometric system design. Related challenges and current research trends are also outlined in this paper
Language Prompt for Autonomous Driving
A new trend in the computer vision community is to capture objects of
interest following flexible human command represented by a natural language
prompt. However, the progress of using language prompts in driving scenarios is
stuck in a bottleneck due to the scarcity of paired prompt-instance data. To
address this challenge, we propose the first object-centric language prompt set
for driving scenes within 3D, multi-view, and multi-frame space, named
NuPrompt. It expands Nuscenes dataset by constructing a total of 35,367
language descriptions, each referring to an average of 5.3 object tracks. Based
on the object-text pairs from the new benchmark, we formulate a new
prompt-based driving task, \ie, employing a language prompt to predict the
described object trajectory across views and frames. Furthermore, we provide a
simple end-to-end baseline model based on Transformer, named PromptTrack.
Experiments show that our PromptTrack achieves impressive performance on
NuPrompt. We hope this work can provide more new insights for the autonomous
driving community. Dataset and Code will be made public at
\href{https://github.com/wudongming97/Prompt4Driving}{https://github.com/wudongming97/Prompt4Driving}
Referring Multi-Object Tracking
Existing referring understanding tasks tend to involve the detection of a
single text-referred object. In this paper, we propose a new and general
referring understanding task, termed referring multi-object tracking (RMOT).
Its core idea is to employ a language expression as a semantic cue to guide the
prediction of multi-object tracking. To the best of our knowledge, it is the
first work to achieve an arbitrary number of referent object predictions in
videos. To push forward RMOT, we construct one benchmark with scalable
expressions based on KITTI, named Refer-KITTI. Specifically, it provides 18
videos with 818 expressions, and each expression in a video is annotated with
an average of 10.7 objects. Further, we develop a transformer-based
architecture TransRMOT to tackle the new task in an online manner, which
achieves impressive detection performance and outperforms other counterparts.
The dataset and code will be available at https://github.com/wudongming97/RMOT.Comment: Accpeted by CVPR 2023. The dataset and code will be available at
https://github.com/wudongming97/RMO
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