bluuebunny/crossref_metadata_2025 huggingface dataset:
Clinical characteristics, risk factors, and thyroid profile of patients admitted with acute left ventricular heart failure from a tertiary hospital in Northeast India
Authors: BORO ANUP KUMAR , GUPTA PRABIR KUMAR , PAUL BIPLAB , RAHMAN HABIBAR , GANG SNEHA , BARMAN ANANYA
Published: April 2023

Introduction:

Heart failure (HF) is a progressive chronic clinical syndrome. Thyroid dysfunction in HF patients has been reported in the literature. We aimed to explore the prevalence of thyroid dysfunction among acute left ventricular failure (LVF) patients admitted to our hospital.

Materials and Methods:

A retrospective study involving 78 patients diagnosed with acute LVF was conducted. Baseline information that included demographics, risk factors, clinical presentations, and biochemical data was recorded. A comparison of acute LVF patients with thyroid dysfunction to those with normal thyroid function was analyzed and documented.

Results:

About 29.5% (n = 23; 63.8 ± 11.4 years) of patients had normal thyroid function and 70.5% (n = 55; 65.3 ± 6 years) had thyroid dysfunction (P = 0.0003). The mean age of the cohort was 64.7 ± 12.4 years and 68% (n = 53) were men. Hypertension was the most common risk factor among both groups (56.5%, n = 13 vs. 67.3%, n = 37; P = 0.0006). Around 13% (n = 3) of patients with normal thyroid function and 20% (n = 11) of patients with thyroid dysfunction expired (P = 0.0325). The most common symptom seen in both groups was shortness of breath (28%, n = 16 vs. 72%, n = 41; P = 0009). There was a high prevalence of HF with reduced ejection fraction (60.8%, n = 14 vs. 65.5%, n = 36; P = 0.0018). Electrocardiography abnormalities were noted in 70.5% (n = 55) of patients of the cohort (65.2%, n = 15 vs. 72.7%, n = 40; P = 0.007). Irregularities in two-dimensional echocardiography and Doppler were seen in 76.5% (n = 59) of patients (69.6%, n = 16 vs. 78.2%, n = 43; P = 0.0004).

Conclusions:

Thyroid dysfunction can cause significant adverse effects on the heart. Early diagnosis and treatment of thyroid abnormalities can reduce and/or prevent the development of serious cardiac problems including HF.
The Effect of Evaporative Cooling Vests on the Physiological and Perceptual Strain Indices of Construction Workers
Authors: Dehghan Habibollah , Mirzabe Mohammad Reza
Published: April 2023

Aim:

One of the most harmful agents in construction sites is heat exposure. The aim of this study was to evaluate the performance of new evaporative cooling vests in construction workers.

Materials and Methods:

This case–control study was implemented on 60 construction workers in hot conditions (air temperature 49.0°, relative humidity 5.5%) in the summer of 2019. In this study, 30 people with cooling vests (case group) and 30 people without cooling vests (control group) were working for 120 min in a hot environment. In both groups, heart rate oral temperature and wet bulb globe temperature (WBGT) index were measured. Moreover, the Perceptual Strain Index (PeSI) and Heat Strain Score Index (HSSI) questionnaires were completed by the workers. Data were analyzed after inter to SPSS16 software.

Results:

All of the WBGT values were higher than occupational exposure limit. The mean and standard deviation (SD) of the work heart rate in the case and control groups, was equal to 111.1 ± 7.6 beats per minute (bpm) and 114.3 ± 7.9 bpm respectively (P < 0.05). Also the average and SD of the oral temperature in the case and control groups, respectively, was equal to 36.36 ± 0.41 and 36.37 ± 0.55. There was no statistically significant difference. Mean and SD of Physiological Strain Index (PSI), in case and control groups, were 2.53 ± 0.66 and 3.64 ± 0.81, respectively. The mean and SD of the PeSI and the HSSI in the case group were 4.64 ± 0.79 and 10.12 ± 1.71, respectively, and in the control group, 6.41 ± 0.85 and 15.88 ± 0.1.43. Statistically, the difference between PSI, PeSI, and HSSI means was significant.

Conclusions:

This study results showed that hot environmental conditions were stressful for construction workers and also Iranian evaporative cooling vests (Hifitcool brand) were able to reduce perceptual and physiological heat strain in construction workers in the hot conditions.
Fusion Protein Consisting of Hemagglutinin Small Subunit and Truncated Nucleoprotein as a Universal Influenza Vaccine Candidate: Starting In-Silico Evaluation Toward In Vitro Expression
Authors: Morshedi Fatemeh , Nazeri Elaheh , Saleh Maryam , Farahmand Behrokh
Published: April 2023

Background:

Influenza virus is a respiratory pathogen, which causes high degree of mortality and morbidity during seasonal epidemics and sporadic pandemics. By selecting conserved antigenic proteins, for example, hemagglutinin small subunit (HA2) and nucleoprotein (NP), we aimed to develop a vaccine based on a fusion protein leading to both cellular and humoral responses that are the most challenging aspects in designing a universal vaccine.

Materials and Methods:

The bioinformatics analysis was performed for HA2-NP structure and function prediction. Primers for the antigenic part of NP were designed using bioinformatics tools. The desired product was amplified via polymerase chain reaction using the designed primers, which was then penetrated into T vector, followed by insertion into pET28a vector in order to construct pET28a/NP. The pET28a/HA2, previously generated in our lab, was digested with the same restriction enzymes as pET28a/NP (HindIII/Xhol). Then, NP was inserted to the downstream region of HA2 to construct pET28a/HA2.

Results:

The generated pET28a/HA2-NP was transformed into Escherichia coli BL21 (DE3). The expression was induced by isopropyl β-d-l-thiogalactopyranoside. The results showed that the antigenic segment of NP was successfully cloned into pET28a/ HA2. The protein band of HA2-NP was observed on sodium dodecyl sulfate polyacrylamide gel electrophoresis, confirmed by Western blotting and purified with Ni-NTA purification system (QIAGEN, Germany).

Conclusion:

As currently available vaccines can cause some allergic reactions, using a chimer protein based on the bioinformatics analysis is continual, safe, and affordable, thus stimulating both cellular and humoral immunity systems. Our construct could potentially provide a basis for a universal vaccine candidate.
Optimized Solvents for the Maceration of Phenolic Antioxidants from Curcuma xanthorrhiza Rhizome using a Simplex Centroid Design
Authors: Nurcholis Waras , Marliani Nelly , Asyhar Rayandra , Minarni Minarni
Published: April 2023

Background:

Curcuma xanthorrhiza Roxb., from the Zingiberaceae family, is a famous plant native to Indonesia that is highly effective in treating diseases due to the various chemical compounds it contains.

Objective:

This study aims to optimize the extraction process for the phenolic content, with its antioxidant activity, from the rhizome of C. xanthorrhiza using different solvent (water, acetone, methanol, and ethanol) systems based on the simplex centroid design using the Design Expert 13.0 program.

Methods and Material:

Total phenolic content (TPC) was analyzed by colorimetry using Follin–Ciocalteu, while the antioxidant activity was measured based on 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging and ferric reducing antioxidant power (FRAP) using a spectrophotometer.

Results:

To measure TPC and DPPH, a special cubic model was used; to measure FRAP, a linear model was utilized. Each model demonstrated a good match with the R2 values for TPC (0.9808), DPPH (0.9583), and FRAP (0.7872). The combination of a mixture of water (0.409), acetone (0.307), and methanol (0.284) with a desirability level of 0.723, resulted in a TPC of 34.112 mg gallic acid equivalent (GAE)/g dry weight (DW), DPPH of 26.533 μmol Trolox equivalent (TE)/g DW, and FRAP of 92.353 μmol TE/g DW. This showed a high extraction efficiency which was optimal.

Conclusions:

The best condition to extract the rhizomes of C. xanthorrhiza was a ternary combination of solvents including water, acetone, and methanol in the proportions of 0.409, 0.307, and 0.284, respectively, with a desirability level of 0.723.
Bixin and Fuxoxanthin Alone and in Combination with Cisplatin Regulate ABCC1 and ABCC2 Transcription in A549 Lung Cancer Cells
Authors: Chandra Ferdy , Tania Teresa F. , Nurcahyanti Agustina D. R.
Published: April 2023

Background:

The ATP-Binding Cassette (ABC) transporter has long been studied to confer drug resistance in human tumors and play important role in metabolic processes and cellular signaling. The overexpression of ABCB1, ABCC1, ABCC2, ABCC3, and ABCG2 leads to decreased sensitivity of lung cancer to cisplatin. At the transcription level, the expression of ABC transporters is highly regulated and requires the complex interplay of factors involved in differentiation and development, cell survival and apoptosis upon intrinsic and environmental stress. The p53 regulation of drug-resistance genes is also complex yet not well understood. Previously, we demonstrated the synergistic interaction between bixin or fucoxanthin with cisplatin in A549 lung cancer cells.

Objectives:

Current study aims to identify whether carotenoids enhancing therapeutic effect of Cisplatin due to the ability to reverse drug resistance associated proteins, such as ABC transporter and regulating the tumor suppressor corresponding gene, p53.

Methods:

Real-Time Quantitative-Polymerase Chain Reaction (RT-qPCR) was performed to estimate the expression level of ABCC1 and ABCC2, and p53 of A549 cell lines in response to carotenoids alone and in combination with cisplatin.

Results and Conclusion:

The administration of bixin or fucoxanthin decreases the expression of ABCC1 and ABCC2. Both carotenoids, either alone or in combination with cisplatin, upregulated p53 gene expression indicating the mechanism of proliferation inhibition and apoptosis occurs via the p53 caspase-independent pathway.
Dyson–Schwinger equations in minimal subtraction
Authors: Balduf Paul-Hermann
Published: April 2023

We compare the solutions of one-scale Dyson–Schwinger equations (DSEs) in the minimal subtraction (MS) scheme to the solutions in kinematic momentum subtraction (MOM) renormalization schemes. We establish that the MS-solution can be interpreted as a MOM-solution, but with a shifted renormalization point, where the shift itself is a function of the coupling. We derive relations between this shift and various renormalization group functions and counterterms in perturbation theory. As concrete examples, we examine three different one-scale Dyson–Schwinger equations: one based on the 1-loop multiedge graph in

D=4

dimensions, one for

D=6

dimensions, and one for mathematical toy model. For each of the integral kernels, we examine both the linear and nine different non-linear Dyson–Schwinger equations. For the linear cases, we empirically find exact functional forms of the shift between MOM and MS renormalization points. For the non-linear DSEs, the results for the shift suggest a factorially divergent power series. We determine the leading asymptotic growth parameters and find them in agreement with the ones of the anomalous dimension. Finally, we present a tentative exact solution to one of the non-linear DSEs of the toy model.
Research on Regenerative Braking Control Strategy of Commercial Vehicles Considering Battery Power Status
Authors: Xie Beichen , Ding Kangjie , Lin Zhenmao
Published: April 2023

Regenerative braking is an effective way to increase the cruising range of vehicles. In commercial vehicles with large vehicle mass, regenerative braking can be maintained in a high-power working state for a long time theoretically because of the large braking torque and long braking time. But in fact, it is often impossible to run at full power because of battery safety problems. In this paper, a control strategy is designed to maintain the maximum power operation of regenerative braking as much as possible. The maximum charging power of the battery is obtained through the battery model, and it is set as the battery limiting parameter. The regenerative braking torque and power are obtained by using the motor model. The eddy current retarder is used to absorb the excess power that the battery can't bear, and the braking torque of the eddy current retarder is calculated. Finally, mechanical braking is used to make up the insufficient braking torque. A set of algorithms is designed based on the brake pedal opening balance of three braking modes. On the premise of ensuring battery safety, try to increase the priority of regenerative braking and reduce the use of mechanical braking. MATLAB is used to simulate the long downhill process of commercial vehicles at the toe of constant slope. Compared with the traditional regenerative braking method, the mechanical braking temperature in this work decreased by 37.62% on average. This work reduces the mechanical braking pressure, reduces the risk of overheating of commercial vehicle brakes, and improves the and safety of the whole vehicle.
Traffic Safety Improvement through Evaluation of Driver Behavior – An Initial Step Towards Vehicle Assessment of Human Operators
Authors: Wang Chengshi , Wang Yue , Alexander Kim , Wagner John
Published: April 2023

In the United States and worldwide, 38,824 and 1.35 million people were killed in vehicle crashes during 2020. These statistics are tragic and indicative of an on-going public health crisis centered on automobiles and other ground transportation solutions. Although the long-term US vehicle fatality rate is slowly declining, it continues to be elevated compared to European countries. The introduction of vehicle safety systems and re-designed roadways has improved survivability and driving environment, but driver behavior has not been fully addressed. A non-confrontational approach is the evaluation of driver behavior using onboard sensors and computer algorithms to determine the vehicle’s “mistrust” level of the given operator and the safety of the individual operating the vehicle. This is an inversion of the classic human-machine trust paradigm in which the human evaluates whether the machine can safely operate in an automated fashion. The impetus of the research is the recognition that human error is responsible for over 90% of motor vehicle crashes. In this paper, a novel mistrust algorithm is introduced that considers both human and vehicle performance to continually update the mistrust metric. The mistrust metric is continually calculated and compared to a priori thresholds leading to safety categorization as normal, aggressive, dangerous, or critical. A full nonlinear virtual automotive simulation has been created with advanced driver safety systems on demand and virtual drivers in traffic to demonstrate the concept. A series of seven driving scenarios have been investigated which feature nine adverse operator behaviors. Numerical results show that the proposed mistrust algorithm, with vehicle ADAS system, can enhance occupant safety. The potential of this traffic safety strategy merits consideration as an alternative driving adaptation for at-risk drivers as autonomous vehicle technology continues to emerge.
Quantitative Multi-Physics Tools for Automotive Wiper Design
Authors: Graham Bradley , Knowles James , Mavros George
Published: April 2023

The primary function of automotive windscreen wipers is to remove excess water and debris to secure a clear view for the driver. Their successful operation is imperative to vehicle occupants’ safety. To avoid reliance on experimental testing there is a need to develop physics-based models that can quantify the effects of design-based decisions on automotive wipers. This work presents a suite of evaluative tools that can provide quantitative data on the effects of design decisions. We analyse the complex non-linear contact interaction between the wiper blade and the automotive screen using finite element analysis, assessing the impact of blade geometry on the contact distribution. The influence of the evolution of normal applied load by the wiper arm is also investigated as to how it impacts the contact distribution evolution. The dynamics of the blade are subsequently analysed using a multiple connected mass spring damper system. Additionally, we apply hydrodynamic lubrication theory to study the residual film thickness post wipe and assess the effect of wiper blade geometry and lubricant composition. Finally, the complete wiper system is studied using a lump dynamic model, and bifurcation analysis is applied to determine areas of instability due to friction induced vibrations. Additionally, the wiper dynamics modelling shows peak frequencies occurring at 30-50Hz, which agrees well with a documented range of chatter frequencies. The friction coefficients calculated within the hydrodynamic model fall within experimentally documented ranges of lubricated sliding friction, μ ≈ 0.1. Furthermore, the areas of operational stability predicted by our bifurcation model coincide with current experimentally determined optimal operational regions for automotive wipers.
Acceleration Performance Data of Mountain Snowmobiles
Authors: Warner Wyatt , Warner Mark
Published: April 2023

Published data relevant to snowmobile crash reconstruction is comparatively limited, especially pertaining to mountain snowmobiling and riding in deep snow. Snowmobiling is a unique motorsport activity as it requires substantial rider input and physical interaction to properly control the vehicle. The added complexities of varying slope angle and snow depth in mountain terrain make application of test data from testing done on flat surfaces less useful when applied to sloped terrain analysis.

New data from testing performed in deep snow conditions on various slopes is presented in this paper. Acceleration tests were performed using two late model mountain snowmobiles from a stop on various slope angles. Additional related factors such as snow density, trenching, and snow mass momentum exchange are also discussed. Comparison of these test results to previously published snowmobile testing data advances the understanding of snowmobile acceleration parameters into mountain terrain.

Significant changes in acceleration performance can result from small changes in slope. Even for the most advanced mountain snowmobiles in loose snow, acceleration becomes more limited as slope increases. Acceleration results are comparable to earlier data, irrespective of snowmobile horsepower and snow conditions. In earlier published data, flat terrain accelerations on packed snow in the range of 0.60g were recorded. In this testing, 0.65 was at the low end of the data, with average full-throttle accelerations of between 0.65g and 0.75g being achieved by both snowmobiles on flat undisturbed powder snow. Keeping in mind that these are different machines, the findings show that traction and horsepower are as significant as snow characteristics when analyzing snowmobile performance.
Vehicle Path-Tracking Control with Dual-Motor SBW System
Authors: Li Meng
Published: April 2023

Improvement of vehicle path-tracking performance not only affects the vehicle driving safety and comfort but is also essential for autonomous driving technology. The current research focuses on vehicle path-tracking control study and application of dual-motor SBW system. The preview driver model is developed by considering the lateral and yaw tracking. MPC (model predictive control) and LQR (linear quadratic regulator) path following controllers are developed to compare the tracking control performance. A steer-by-wire (SBW) system of dual-motor configuration is designed with permanent magnet synchronous motor (PMSM) control scheme. Finally, the proposed control methods are verified with different driving cases, which shows that the system can effectively achieve small tracking errors in the simulation, and also can be applied in the future autonomous driving or advanced driver assistance system to maintain the lateral and yaw errors within a safe range during path-tracking.
Designing Dynamic Wireless Power Transfer Corridors for Heavy Duty Battery Electric Commercial Freight Vehicles
Authors: Sujan Vivek Anand , Siekmann Adam , Tennille Sarah , Tsybina Eve
Published: April 2023

The use of wireless power transfer systems, consisting of inductive electrical coils on the vehicle and the power source may be designed for dynamic operations where the vehicle will absorb energy at highway speeds from transmitting coils in the road. This has the potential to reduce the onboard energy storage requirements for vehicles while enabling significantly longer missions. This paper presents an approach to architecting a dynamic wireless power transfer corridor for heavy duty battery electric commercial freight vehicles. By considering the interplay of roadway power capacity, roadway and vehicle coil coverage, seasonal road traffic loading, freight vehicle class and weight, vehicle mobility energy requirements, on-board battery chemistry, non-electrified roadway vehicle range requirements, grid capacity, substation locations, and variations in electricity costs, we minimize the vehicle TCO by architecting the electrified roadway and the vehicle battery simultaneously. The idea optimizes battery size and chemistry so that the depth of discharge between recharge events and expected life are balanced, thus fully utilizing the energy available throughout the course of the battery system's life. The approach is illustrated by applying it to the I-75 freight corridor, where the framework developed may be expanded and applied to a larger interstate system, expanded regional corridor, or other transportation network.
Development of a Heavy-Duty Electric Vehicle Integration and Implementation (HEVII) Tool
Authors: Badheka Aaditya , Eagon Matthew John , Fakhimi Setayesh , Wiringa Peter , Miller Eric , Kotz Andrew , Northrop William
Published: April 2023

As demand for consumer electric vehicles (EVs) has drastically increased in recent years, manufacturers have been working to bring heavy-duty EVs to market to compete with Class 6-8 diesel-powered trucks. Many high-profile companies have committed to begin electrifying their fleet operations, but have yet to implement EVs at scale due to their limited range, long charging times, sparse charging infrastructure, and lack of data from in-use operation. Thus far, EVs have been disproportionately implemented by larger fleets with more resources. To aid fleet operators, it is imperative to develop tools to evaluate the electrification potential of heavy-duty fleets. However, commercially available tools, designed mostly for light-duty vehicles, are inadequate for making electrification recommendations tailored to a fleet of heavy-duty vehicles. The main challenge is that light-duty tools do not estimate real-time vehicle mass, a factor that has a disproportionate impact on the energy consumption of large commercial vehicles. The Heavy-Duty Electric Vehicle Integration and Implementation (HEVII) tool advances the state of the art in evaluating electrification potential and infrastructure requirements for fleets of commercial vehicles. In this work, the HEVII tool is demonstrated with non-uniformly sampled telematics data from an existing fleet to assess the suitability for electrification of each individual vehicle, determine optimal locations for charging infrastructure to support a fleet of EVs and analyze associated costs. Payload mass is predicted using sparse ground-truth data for all input drive cycles and an initial data analysis is conducted to assess the characteristics driving behaviors and energy consumption of the fleet using an adaptable vehicle model. Battery size requirements are determined by applying a novel charger placement algorithm to maximize routes that are viable for EVs and balance time delays with infrastructure development costs. This work details and demonstrates the different aspects of the HEVII tool, presenting preliminary results from an example use case.
Combustion Chamber Development to Maximize the Performance of the Hydrogen Combustion Engine for the T1 Ultimate Category of the Dakar Rally Competition
Authors: Durand Thomas , Adomeit Philipp , Blomberg Michael , Jeihouni Yousef , Michelet Francois , Combemale Loic , Meyer Serge
Published: April 2023

As the world strives toward the common goal of carbon neutrality by 2050, motorsport cannot be allowed to stand alone as an exception. A gradual energy transition is clearly underway in the automotive industry but has already begun in motorsport as well. Among other initiatives, the Dakar Rally and the FIA have created the T1 ultimate category for prototypes powered by low-carbon fuels, including hydrogen. The Dakar is the pinnacle of off-road endurance rally competitions. It offers a great opportunity to ORECA Magny-Cours and FEV to expose their jointly developed internal combustion engine (ICE), fuelled with hydrogen only, to extreme conditions. In addition, the racing environment imposes a unique pace of development which can serve as a catalyst for spurring the H2-ICE technology. Moreover, a hydrogen powered engine is an interesting fit for motorsports because it combines high power output, a relatively long driving range and driving pleasure with an excellent carbon footprint.

This article outlines how ORECA Magny-Cours and FEV are currently converting a gasoline racing engine to hydrogen direct injection to meet the numerous challenges of the Dakar Rally. In several development steps, a combustion chamber was newly developed that is tailored to gaseous hydrogen combustion. A high level of charge motion and optimized mixture formation have ultimately been realized using FEV’s dedicated H2-ICE simulation tool chain. Design changes resulting from the simulation results are incorporated into the engine. Further thermodynamic investigations on an engine test bench will be undertaken by ORECA Magny-Cours to maximize performance while ensuring knock free operation and best engine efficiency. Although there are still development hurdles to overcome, the combined ORECA/FEV experience will bring a viable carbon neutral powertrain solution to compete in the future Dakar Rally.
A Hybrid Physical and Data-Driven Framework for Improving Tire Force Calculation Accuracy
Authors: Yang Huanning , Li Zihan , Yang BoXiong , Wang Ping
Published: April 2023

The accuracy of tire forces directly affects the vehicle dynamics model precision and determines the ability of the model to develop the simulation platform or design the control strategy. In the high slip angle, due to the complex interactions at tire-road interfaces, the forces generated by the tires are high nonlinearity and uncertainty, which pose issues in calculating tire force accurately. This paper presents a hybrid physical and data-driven tire force calculation framework, which can satisfy the high nonlinearity and uncertainty condition, improve the model accuracy and effectively leverage prior knowledge of physical laws. The parameter identification for the physical tire model and the data-based compensation for the unknown errors between the physical tire model and actual tire force data are contained in this framework. First, the parameters in the selected combined-slip Burckhardt tire model are identified by the nonlinear least square method with tire test data. Then, the unknown nonlinear errors between the physical model and actual tire force are compensated by a neural network using the large data sets from indoor tire test facilities, including pure- and combined-slip conditions. Finally, the tire force calculation comparison illustrates that the proposed hybrid physical and data-driven tire force calculation framework can effectively improve the model accuracy, reflect the tire characteristics more accurately, adapt to different conditions, and is suitable for establishing a vehicle dynamics model.
Sliding Mesh Fan Approach Using Open-Source Computational Fluid Dynamics to Investigate Full Vehicle Automotive Cooling Airflows
Authors: Vilchis Contreras Eloy , Guzman Arturo , Doroudian Mark
Published: April 2023

Cooling airflow is an essential factor when it comes to vehicle performance and operating safety. In recent years, significant efforts have been made to maximize the flow efficiency through the heat exchangers in the under-hood compartment. Grille shutters, new fan shapes, better sealings are only some examples of innovations in this field of work.

Underhood cooling airflow simulations are an integral part of the vehicle development process. Especially in the early development phase, where no test data is available to verify the cooling performance of the vehicle, computational fluid dynamics simulations (CFD) can be a valuable tool to identify the lack of fan performance and to develop the appropriate strategy to achieve airflow goals through the heat exchangers.

For vehicles with heat exchangers in the underhood section the airflow through those components is of particular interest. Since the cooling fan is the main driver of the airflow in the underhood compartment at low vehicle speeds, its accurate modeling is a prerequisite for a higher fidelity airflow prediction.

In this work, some aspects of fan modeling for cooling airflow are discussed in more detail, and the most common modeling approaches are briefly outlined.

Furthermore, transient simulations using the sliding mesh (SM) procedure are presented that allow for a higher fidelity prediction of the flow field in the underhood compartment.

To determine an accurate and cost-efficient computational sliding mesh (SM) setup, detailed numerical studies of a fan in a full vehicle were performed by using different time steps on an open-source code. To prove the applicability of the proposed method for full vehicle simulations, the procedure is physically tested in a drive-cell in the Fiat Chrysler Automobiles (FCA US) facilities and the flow through the heat exchanges is compared to the result obtained by the transient sliding mesh simulation as well as to the results obtained with three classical fan models (Blade angle, fan curve and MRF model).
Experimental Analysis and Dynamic Optimization Design of Hinge Mechanism
Authors: Zhang Suo , Gao Yunkai , Chang Mengjie
Published: April 2023

Optimization design of hard point parameters for hinge mechanism has been paid more attention in recent years, attributable to their significant improvement in dynamic performance. In this paper, the experimental analysis and dynamic optimization design of hinge mechanism is performed. The acceleration measurement experiments are carried out at different arrangement points and under different working conditions. Furthermore, the accuracy of established multi-body dynamics model is verified by three-axis accelerometer measurement experiment. In addition, sensitivity analysis for electric strut and gas strut coordinates is performed and shows that the Y coordinate of the lower end point of the electric strut is the design variable that has the greatest impact on the responses. To improve the dynamic performance of the hinge mechanism, a surrogate-assisted NSGA-II multi-objective optimization design framework for hard point coordinates of struts, combining the radial basis neural network (RBF), polynomial response surface model (PRS), NSGA-II is carried out to obtain the Pareto frontier. Finally, a multi-objective decision-making method inspired by TOPSIS and entropy analysis is performed to calculate the unique best from the Pareto frontier. Finally, the optimized results shown that the optimized hinge mechanism is better than the original one, i.e., the dynamic responses are improved by 25.2%, 39.8%, 39.8% and 58.8% for door mass center acceleration, peak force of rotating pair 1, peak force of rotating pair 2 and motor driving force.
Introduction of the Small Test Robot for Individuals in Dangerous Environments (STRIDE) Platform for Use in ADAS Testing
Authors: Bartholomew Meredith , Helber Nicholas , Nguyen An , Zagorski Scott , Heydinger Gary
Published: April 2023

The use of platforms to carry vulnerable road user (VRU) targets has become increasingly necessary with the rise of automated driver assistance systems (ADAS) on vehicles. These ADAS features must be tested in a wide variety of collision-imminent scenarios which necessitates the use of strikable targets carried by an overrun-able platform. To enable the testing of ADAS sensors such as lidar, radar, and vision systems, S-E-A, a longtime supplier of vehicle testing equipment, has created the STRIDE robotic platform (Small Test Robot for Individuals in Dangerous Environments). This platform contains many of the key ingredients of other platforms on the market, such as a hot-swappable battery, E-stop, and mounting points for targets. However, the STRIDE platform additionally provides features which can enable non-routine testing such as: turning in place, driving with an app on a mobile phone, user-scripting, and steep grade climbing capability. The combination of these elements makes STRIDE an innovative product which can fulfill the needs of specialized use cases and enable the development of more robust test scenarios.
Evaluating Automated Vehicle Scenario Navigation Using the Operational Safety Assessment (OSA) Methodology
Authors: Como Steven , Wishart Jeffrey
Published: April 2023

The operational safety of Automated Driving System-equipped vehicles (AVs) is a critical issue with AVs being deployed on public roads. Methodologies for evaluating the operational safety are therefore necessary to maintain public safety. One possible approach is a safety case established by the AV developer that uses evidence to support a structured argument that the AV exhibits a given level of operational safety. One of the key components of a safety case for AVs is a set of testing results showing behavioral competency in a variety of scenarios within the AV’s operational design domain (ODD). The Institute of Automated Mobility (IAM) has previously published operational safety assessment (OSA) metrics along with a means to evaluate the severity of violations of the safety envelope-type OSA metrics for navigation of individual scenarios in the proposed OSA Methodology. The objective of the OSA Methodology is to objectively quantify the safety performance of each scenario navigated by the AV, with the aggregate quantifications to be included in the AV’s safety case. This work expands on the introduction of the OSA Methodology to (1) include more OSA metrics (beyond the safety envelope type) with clearly defined formulations for the severity of metric violation formulations, and (2) propose a methodology for interpreting the various OSA metric violation measurements to result in the desired quantification of the AV’s safety performance of a scenario navigation that is composed of evaluations of collision events, near-miss events, and non-collision events. The OSA Methodology is implemented in various simulation software and in real-world testing results at an IAM testbed to validate the concept. The results show a promising test result interpretation methodology that can be incorporated into a safety case framework to help ensure AV operational safety.
Material and Bonding Conditions Optimization of Monocoque Inserts Based on Formula Student Electric China
Authors: Kang Yuxin , Guo Wei , Wu Shukai
Published: April 2023

In the Formula Student Electric China (FSEC), the body structure is generally divided into two types, truss steel tube body and carbon fiber load-bearing body (monocoque). The monocoque is loved by Formula Student teams around the world because it has a higher stiffness and lighter weight than the truss steel tube body. With the widespread application of monocoque, it also brings more problems. Due to the use of the monocoque, the connection between each component and the body was changed from the welding of the original truss steel pipe frame to a bolted connection. However, the bolted connection will provide a large preload force to the monocoque, resulting in the monocoque easily crushed in the local, so it is necessary to pre-bury an enhanced part in the monocoque to ensure the connection strength, that is, the embedded part. At present, aluminum plug-ins after topological hollow processing are being used. Although the weight is reduced a lot, the assembly cross-sectional area is reduced, resulting in the inserts are easy to loosen, the connection is unstable, and even the lifting ears may be loose under severe working conditions, so that the vehicle is in an extremely unsafe state. It is necessary to optimize the material and bonding conditions of the inserts. In this paper, two engineering plastics, PPS and PPS with 30% glass fiber (PPS30), were selected and the bonding conditions were optimized in terms of several variables. The results show that the bonding strength is improved by the use of PPS30 and the optimization of the bonding conditions.
New Radiant Heater Structure which Combines Warmth and Safety for EV Range Extension
Authors: Sago Yasuhiro , Ishikawa Kimitake , Seki Hideki , Tanaka Yusuke
Published: April 2023

The use of EVs has accelerated worldwide to reduce CO2 emissions and reduce environmental impact. One of the major issues for EVs is their decrease of electric range during heating in winter. This is because the HVAC (Heating Ventilation and Air Conditioning) system with electric heater or HP (Heat pump) system consumes a lot of energy to warm the occupants. That's why many vehicle OEMs consider not only convection heating system with HVAC, but also other systems such as contact heating devices, seat heaters, or steering wheel heaters. Those devices are more efficient at warming the human body, therefore the heating system can save energy and improve the occupant’s comfort. In this paper, the thighs, knees and shins, which cannot be heated by a seat heater, are heated more efficiently than by convection heating by using a high-temperature radiant heater in which the surface heats up to 100°C or more in 1 minute. It contributes to improving comfort and saving energy in transient periods of low temperature condition. The main feature of this technology is a thin-film heater. Low heat capacity due to the thin structure of heating wires and low heat conduction due to the structure surrounding wires with resin of low heat conduction can suppress the inflow of heat to the occupant from the heater surface when the occupant comes into contact with it. The surface temperature drops rapidly when the occupant is in contact with the heater surface due to this structure and the skin temperature of the occupant does not exceed 52°C. Therefore, the heating performance can be compatible with the safety requirements, and it contributes to energy saving.
Study on Driving Forms and Control of Engine Cooling Fan
Authors: Xu Zichen , Wang Xihui , Shangguan Wenbin , Wang Xinling , Duan Yaolong
Published: April 2023

The influence of engine cooling fan on the working state of engine cooling system under different driving forms and control strategy is studied, and a simulation model of engine thermal management system of a commercial vehicle is established. The model takes into account the measured performance parameters of the cooling system components, the gear shift logic of the transmission, the effect of vehicle speed on the airflow rate of the radiator, and proposes a modeling method for different cooling fan driving forms. The performance parameters such as engine outlet coolant temperature and corresponding cooling fan speed under different vehicle speeds and engine loads are calculated and analyzed by using the established model. The road measurement test of the engine thermal management system under the same working condition was carried out to read the relevant data from the engine ECU and confirm the reliability of the data. The correctness of the model is proved by the comparison between the model calculation results and the test results. Based on the established model, the working characteristics of the cooling fan driven by the electronically controlled silicone oil clutch are analyzed, and the improvement method of the control strategy of the electronically controlled silicone oil clutch is proposed. The results show that the cooling fan driven by the electronically controlled silicone oil clutch can adaptively adjust the fan speed, reduce the power consumption of the engine, and make the engine work at the optimal temperature by using the improved control strategy of the electronically controlled silicone oil clutch established in this paper.
Empirical Equations of Changes in Aerodynamic Drag Based on Direct On-Track Road Load Measurements for Multi-Vehicle Platoons
Authors: Duoba Michael
Published: April 2023

Considerable effort is currently being focused on emerging vehicle automation technologies. Engineers are making great strides in improving safety and reliability, but they are also exploring how these new technologies can enhance energy efficiency. This study focuses on the changes in aerodynamic drag associated with coordinated driving scenarios, also known as “platooning.” To draw sound conclusions in simulation or experimental studies where vehicle speed and gaps are controlled and coordinated, it is necessary to have a robust quantitative understanding of the road load changes associated with each vehicle in the platoon. Many variables affect the drag of each vehicle, such as each gap length, vehicle type/size, vehicle order and number of vehicles in the platoon. The effect is generally understood, but there are limited supporting data in the literature from actual test vehicles driving in formation. This study uses a practical approach to quantify road load changes in each vehicle using axle torque sensors to directly measure the load required to maintain steady-state speeds while in different platoon configurations (compared to driving solo). Three test vehicles were used, which varied in size and type: a passenger car, a mid-size SUV, and a full-size pickup truck. A control computer in each vehicle sent commands to the vehicle accelerator input to control the speed and gap based on radar feedback. The final product of the test program is a set of empirical equations that estimate drag changes for two- and three-vehicle platoons at highway speeds (88-112 km/hr) with varying vehicle and platoon configuration parameters.
Estimation of Seated Driver Eye Height based on Standing Height, Weight, Seatback Angle, and Seat Bottom Angle
Authors: Roescher Todd , Randles Bryan , Welcher Judson
Published: April 2023

This paper presents an analysis on the position of driver eye height as a function of their standing height, weight, biological sex, seat back angle and seat bottom angle. Typically, eye heights are estimated based on standing height, or measured from a rigid seated position with a vertical seat back. While reasonably close, these estimated eye heights are generally not correct for individuals seated in deformable vehicle seats with non-vertical seat back angles. Thus, these measurements tend to overestimate the participants eye height in more ecologically probable scenarios, such as driver eye height while operating a vehicle. In this study, eye measurements were taken from a standing position and while seated on a rigid surface and then compared to the same participant’s eye height measured while seated on six different representative vehicle seats with seat back angles of 20, 25, and 30 degrees respectively. Furthermore, this study also measured for-aft positioning of the participant’s eyes relative to the anterior edge of the head restraint at each seat position. This study utilized three pickup truck seats, two light passenger vehicle seats, and one sport utility vehicle seat. This data outlines a methodology that can be used to estimate eye positions of other adult humans in deformable vehicle seats when only their standing height, weight, and biological sex are known, or even more precisely when general seat geometry is also known. This allows for more accurate recreations of first-person point-of-view lines of sight or visual obstruction analysis.
An Approach to Model a Traffic Environment by Addressing Sparsity in Vehicle Count Data
Authors: Patil Mayur , Tulpule Punit , Midlam-Mohler Shawn
Published: April 2023

For realistic traffic modeling, real-world traffic calibration data is needed. These data include a representative road network, road users count by type, traffic lights information, infrastructure, etc. In most cases, this data is not readily available due to cost, time, and confidentiality constraints. Some open-source data are accessible and provide this information for specific geographical locations, however, it is often insufficient for realistic calibration. Moreover, the publicly available data may have errors, for example, the Open Street Maps (OSM) does not always correlate with physical roads. The scarcity, incompleteness, and inaccuracies of the data pose challenges to the realistic calibration of traffic models. Hence, in this study, we propose an approach based on spatial interpolation for addressing sparsity in vehicle count data that can augment existing data to make traffic model calibrations more accurate. This study will primarily assist in traffic modeling for Fuel Efficiency (FE) of individual Connected and Autonomous Vehicles (CAV) estimation (road safety and fleet-wide efficiency are out of the scope). We propose a process to identify typical characteristics of trips that are most critical for CAV’s FE from single-vehicle data. We then use this data along with vehicle counts to calibrate the traffic model such that the drive cycle characteristics of the Vehicle Under Test (VUT) are matched with the data collected from the real test. This calibration procedure ensures that the vehicle in the simulation environment observes speed profiles that allow realistic FE estimates. In this paper, the traffic modeling calibration is performed in Simulation of Urban MObility (SUMO) where we demonstrate the approach for the Columbus, OH metropolitan area. The available data is in the form of edge-based traffic count commonly known as Annual Average Daily Traffic (AADT), provided by the Ohio Department of Transportation (ODOT).
A Comprehensive Analysis of Methods to Write Requirements for Machine Learning Components used in Autonomous Vehicles
Authors: Madala Kaushik , Krishnamoorthy Jayalekshmi , Gil Batres Andrea , Avalos Gonzalez Carlos , Chang Melody
Published: April 2023

Machine learning components are widely used in autonomous vehicles for implementing functionalities related to perception and planning. To verify if the vehicle-level functionalities are as specified, one of the widely used approaches is requirements-based testing. However, writing testable requirements for machine learning components can be challenging since the machine learning outcomes are seldom known in advance. Nevertheless, it is important to have a specification that details the expected behavior from machine learning components. In this paper, we discuss different approaches to write a specification for machine learning algorithms that are used in autonomous vehicles. These approaches include natural language requirements, user stories, use case specifications, behavioral diagrams, data as requirements, and formal specification methods. We also propose a tabular specification method for specifying requirements of machine learning algorithms. We use a sample operational design domain (ODD) and system architecture to discuss the advantages and disadvantages of each of the techniques. We also discuss which approaches can aid with testing as well as error analysis of the model generated using the machine learning algorithms.