bluuebunny/crossref_metadata_2025 huggingface dataset:
Construction of CDKN2A-related competitive endogenous RNA network and identification of GAS5 as a prognostic indicator for hepatocellular carcinoma
Authors: Pan Yong , Zhang Yi-Ru , Wang Ling-Yun , Wu Li-Na , Ma Ying-Qiu , Fang Zhou , Li Shi-Bo
Published: April 2024

BACKGROUND

Competitive endogenous RNA (ceRNA) is an innovative way of gene expression modulation, which plays a crucial part in neoplasia. However, the intricacy and behavioral characteristics of the ceRNA network in hepatocellular carcinoma (HCC) remain dismal.

AIM

To establish a cyclin dependent kinase inhibitor 2A (CDKN2A)-related ceRNA network and recognize potential prognostic indicators for HCC.

METHODS

The mutation landscape of CDKN2A in HCC was first explored using the cBioPortal database. Differential expression analysis was implemented between CDKN2Ahigh and CDKN2Alow expression HCC samples. The targeted microRNAs were predicted by lncBasev3.0, and the targeted mRNAs were predicted by miRDB, and Targetscan database. The univariate and multivariate analysis were utilized to identify independent prognostic indicators.

RESULTS

CDKN2A was frequently mutated and deleted in HCC. The single-cell RNA-sequencing analysis revealed that CDKN2A participated in cell cycle pathways. The CDKN2A-related ceRNA network-growth arrest specific 5 (GAS5)/miR-25-3p/SRY-box transcription factor 11 (SOX11) was successfully established. GAS5 was recognized as an independent prognostic biomarker, whose overexpression was correlated with a poor prognosis in HCC patients. The association between GAS5 expression and methylation, immune infiltration was explored. Besides, traditional Chinese medicine effective components targeting GAS5 were obtained.

CONCLUSION

This CDKN2A-related ceRNA network provides innovative insights into the molecular mechanism of HCC formation and progression. Moreover, GAS5 might be a significant prognostic biomarker and therapeutic target in HCC.
Risk factors for hepatocellular carcinoma associated with hepatitis C genotype 3 infection: A systematic review
Authors: Farooq Hamzah Z , James Michael , Abbott Jane , Oyibo Patrick , Divall Pip , Choudhry Naheed , Foster Graham R
Published: April 2024

BACKGROUND

Hepatitis C virus (HCV) is a blood-borne virus which globally affects around 79 million people and is associated with high morbidity and mortality. Chronic infection leads to cirrhosis in a large proportion of patients and often causes hepatocellular carcinoma (HCC) in people with cirrhosis. Of the 6 HCV genotypes (G1-G6), genotype-3 accounts for 17.9% of infections. HCV genotype-3 responds least well to directly-acting antivirals and patients with genotype-3 infection are at increased risk of HCC even if they do not have cirrhosis.

AIM

To systematically review and critically appraise all risk factors for HCC secondary to HCV-G3 in all settings. Consequently, we studied possible risk factors for HCC due to HCV-G3 in the literature from 1946 to 2023.

METHODS

This systematic review aimed to synthesise existing and published studies of risk factors for HCC secondary to HCV genotype-3 and evaluate their strengths and limitations. We searched Web of Science, Medline, EMBASE, and CENTRAL for publications reporting risk factors for HCC due to HCV genotype-3 in all settings, 1946-2023.

RESULTS

Four thousand one hundred and forty-four records were identified from the four databases with 260 records removed as duplicates. Three thousand eight hundred and eighty-four records were screened with 3514 excluded. Three hundred and seventy-one full-texts were assessed for eligibility with seven studies included for analysis. Of the seven studies, three studies were retrospective case-control trials, two retrospective cohort studies, one a prospective cohort study and one a cross-sectional study design. All were based in hospital settings with four in Pakistan, two in South Korea and one in the United States. The total number of participants were 9621 of which 167 developed HCC (1.7%). All seven studies found cirrhosis to be a risk factor for HCC secondary to HCV genotype-3 followed by higher age (five-studies), with two studies each showing male sex, high alpha feto-protein, directly-acting antivirals treatment and achievement of sustained virologic response as risk factors for developing HCC.

CONCLUSION

Although, studies have shown that HCV genotype-3 infection is an independent risk factor for end-stage liver disease, HCC, and liver-related death, there is a lack of evidence for specific risk factors for HCC secondary to HCV genotype-3. Only cirrhosis and age have demonstrated an association; however, the number of studies is very small, and more research is required to investigate risk factors for HCC secondary to HCV genotype-3.
Pathologically successful conversion hepatectomy for advanced giant hepatocellular carcinoma after multidisciplinary therapy: A case report and review of literature
Authors: Chu Ju-Hang , Huang Lu-Yao , Wang Ya-Ru , Li Jun , Han Shi-Long , Xi Hao , Gao Wen-Xue , Cui Ying-Yu , Qian Ming-Ping
Published: April 2024

BACKGROUND

Hepatocellular carcinoma (HCC) is one of the leading causes of death due to its complexity, heterogeneity, rapid metastasis and easy recurrence after surgical resection. We demonstrated that combination therapy with transcatheter arterial chemoembolization (TACE), hepatic arterial infusion chemotherapy (HAIC), Epclusa, Lenvatinib and Sintilimab is useful for patients with advanced HCC.

CASE SUMMARY

A 69-year-old man who was infected with hepatitis C virus (HCV) 30 years previously was admitted to the hospital with abdominal pain. Enhanced computed tomography (CT) revealed a low-density mass in the right lobe of the liver, with a volume of 12.9 cm × 9.4 cm × 15 cm, and the mass exhibited a “fast-in/fast-out” pattern, with extensive filling defect areas in the right branch of the portal vein and an alpha-fetoprotein level as high as 657 ng/mL. Therefore, he was judged to have advanced HCC. During treatment, the patient received three months of Epclusa, three TACE treatments, two HAIC treatments, three courses of sintilimab, and twenty-one months of lenvatinib. In the third month of treatment, the patient developed severe side effects and had to stop immunotherapy, and the Lenvatinib dose had to be halved. Postoperative pathological diagnosis indicated a complete response. The patient recovered well after the operation, and no tumor recurrence was found.

CONCLUSION

Multidisciplinary conversion therapy for advanced enormous HCC caused by HCV infection has a significant effect. Individualized drug adjustments should be made during any treatment according to the patient's tolerance to treatment.
Primary pancreatic peripheral T-cell lymphoma: A case report
Authors: Bai Yan-Liang , Wang Li-Jie , Luo Hui , Cui Ya-Bin , Xu Jin-Hui , Nan Hui-Jie , Yang Pei-Yao , Niu Jun-Wei , Shi Ming-Yue
Published: April 2024

BACKGROUND

Primary pancreatic lymphoma (PPL) is an exceedingly rare tumor with limited mention in scientific literature. The clinical manifestations of PPL are often nonspecific, making it challenging to distinguish this disease from other pancreatic-related diseases. Chemotherapy remains the primary treatment for these individuals.

CASE SUMMARY

In this case study, we present the clinical details of a 62-year-old woman who initially presented with vomiting, abdominal pain, and dorsal pain. On further evaluation through positron emission tomography-computed tomography, the patient was considered to have a pancreatic head mass. However, subsequent endoscopic ultrasonography-guided fine needle aspiration (EUS-FNA) revealed that the patient had pancreatic peripheral T-cell lymphoma, not otherwise specified (PTCL-NOS). There was a substantial decrease in the size of the pancreatic mass after the patient underwent a cycle of chemotherapy comprised of brentuximab vedotin, decitabine, and oxaliplatin (brentuximab vedotin and Gemox). The patient had significant improvement in radiological findings at the end of the first cycle.

CONCLUSION

Primary pancreatic PTCL-NOS is a malignant and heterogeneous lymphoma, in which the clinical manifestations are often nonspecific. It is difficult to diagnose, and the prognosis is poor. Imaging can only be used for auxiliary diagnosis of other diseases. With the help of immunostaining, EUS-FNA could be used to aid in the diagnosis of PPL. After a clear diagnosis, chemotherapy is still the first-line treatment for such patients, and surgical resection is not recommended. A large number of recent studies have shown that the CD30 antibody drug has potential as a therapy for several types of lymphoma. However, identifying new CD30-targeted therapies for different types of lymphoma is urgently needed. In the future, further research on antitumor therapy should be carried out to improve the survival prognosis of such patients.
The 2023 Dengue Outbreak in Bangladesh: Exploring the Epidemiology in Hospitalized Patients
Authors: Anika Urby Saraf , Islam Muna , Mou Fatema E Nur , Saha Mrinal , Deb Aparna , Tui Rubaiya Rahman , Manzoor Joarder Rakeen , Jesmin Afroza , Martuja Ayesha , Fardous Jannatul , Sharif Mohiuddin , Rafi Md. Abdur , Hasan Mohammad Jahid
Published: April 2024

For the past two decades, Bangladesh has faced recurrent dengue outbreaks, with the most recent occurring in 2023. We investigated the socioeconomic, clinical, and laboratory aspects of patients diagnosed with dengue during this outbreak. This observational study was conducted from July to September 2023 at Dhaka Medical College Hospital and Chittagong Medical College Hospital, and included 450 confirmed cases of dengue. Sociodemographic information was collected via face-to-face interviews, clinical examinations, and laboratory testing, which was done within 24 hours of admission. Dengue severity was classified according to the 2009 WHO dengue guidelines. Notably, 17% of patients experienced severe dengue, and 89% of those with nonsevere cases exhibited at least one warning sign. Most patients were young adults (mean age, 33 years), with a nearly equal male-to-female ratio. Common clinical presentations included fever (95%), myalgia (62%), and headache (58%), whereas warning signs such as vomiting (54%) and abdominal pain (39%) were prevalent. Plasma leakage indicators, including ascites, pleural effusion, and edema, were found predominantly in severe cases. Laboratory findings revealed leukopenia, thrombocytopenia, and elevated hepatic enzymes (alanine aminotransferase and aspartate aminotransferase) in nearly half the patients. An elevated hematocrit level was associated with severe dengue. We report that a substantial number of patients developed severe dengue during the epidemic in 2023, and provide detailed clinical–epidemiological profiles of the patients, offering valuable insight into management of dengue cases.
A Method for Determining Mileage Accumulation for Robustness Validation of Advanced Driver Assistance Systems (ADAS) Features
Authors: Almasri Hossam , Fan Hsing-Hua , Mudunuri Venkateswara Raju
Published: April 2024

Robustness testing of Advanced Driver Assistance Systems (ADAS) features is a crucial step in ensuring the safety and reliability of these systems. ADAS features include technologies like adaptive cruise control, lateral and longitudinal controls, automatic emergency braking, and more. These systems rely on various sensors, cameras, radar, lidar, and software algorithms to function effectively. Robustness testing aims to identify potential vulnerabilities and weaknesses in these systems under different conditions, ensuring they can handle unexpected scenarios and maintain their performance.

Mileage accumulation is one of the validation methods for achieving robustness. It involves subjecting the systems to a wide variety of real-world driving conditions and driving scenarios to ensure the reliability, safety, and effectiveness of the ADAS features. Following ISO 21448 (Safety of the intended functionality-SOTIF), known hazardous scenarios can be tested and validated through robustness testing and validation. Unknown hazardous scenarios can be exposed and identified as known hazardous scenarios through accumulated miles. However, determining the mileage needed for acceptance still poses a challenge.

This paper presents a potential methodology utilizing the Sequential Probability Ratio Test (SPRT) as acceptance criteria to determine the required mileage accumulation and to evaluate the robustness of the ADAS feature. Selection of the baseline ratio for SPRT depends on the maturity level of the ADAS features and Operational Design Domain (ODD) / Object Event Detection Response (OEDR) coverage. Furthermore, SPRT utilizes the likelihood ratio approach to establish an acceptable, rejection and continuation regions. Number of hours/miles of accumulation and the number of mishaps/hazards are the two main factors for the robustness example shown in the paper. This paper demonstrates how to use these established regions to gain various levels of confidence and prove out the robustness of the ADAS features.
Rapid Development of an Autonomous Vehicle for the SAE AutoDrive Challenge II Competition
Authors: Ashokkumar Sriram , Jayendra Anirudh , Tobin Sam , Leykin Ariel , Stegeman Robert , Dashora Abhiraj , Look Bryan , Koenig Joseph , Hu Brian , Crooks Mason , Mahajan Ishaan , Boopathy Pravin , Krishnakumar Mukund , Batagoda Nevindu , Wang Han , Young Aaron , Freire Victor , Bower Glenn , Xu Xiangru , Negrut Dan
Published: April 2024

The SAE AutoDrive Challenge II is a four-year collegiate competition dedicated to developing a Level 4 autonomous vehicle by 2025. In January 2023, the participating teams each received a Chevy Bolt EUV. Within a span of five months, the second phase of the competition took place in Ann Arbor, MI. The authors of this contribution, who participated in this event as team Wisconsin Autonomous representing the University of Wisconsin–Madison, secured second place in static events and third place in dynamic events. This has been accomplished by reducing reliance on the actual vehicle platform and instead leveraging physical analogs and simulation. This paper outlines the software and hardware infrastructure of the competing vehicle, touching on issues pertaining sensors, hardware, and the software architecture employed on the autonomous vehicle. We discuss the LiDAR-camera fusion approach for object detection and the three-tier route planning and following systems. One of the defining aspects of our approach was leveraging early simulation and the use of physical analogs, which accelerated the development of the autonomy algorithms. In the process, we established a rapid autonomous vehicle development methodology that will anchor our technical effort in the third stage of the SAE AutoDrive Challenge II competition.
Simulative Assessments of Cyclic Queuing and Forwarding with Preemption in In-Vehicle Time-Sensitive Networking
Authors: Luo Feng , Wang Zitong , Ren Yi , Wu Mingzhi , Zhang Xiaoxian
Published: April 2024

The current automotive industry has a growing demand for real-time transmission to support reliable communication and for key technologies. The Time-Sensitive Networking (TSN) working group introduced standards for reliable communication in time-critical systems, including shaping mechanisms for bounded transmission latency. Among these shaping mechanisms, Cyclic Queuing and Forwarding (CQF) and frame preemption provide deterministic guarantees for frame transmission. However, despite some current studies on the performance analysis of CQF and frame preemption, they also need to consider the potential effects of their combined usage on frame transmission. Furthermore, there is a need for more research that addresses the impact of parameter configuration on frame transmission under different situations and shaping mechanisms, especially in the case of mechanism combination. Firstly, this paper comprehensively reviews the schedulability analysis of the combined usage of CQF and frame preemption based on Compositional Performance Analysis (CPA). This paper summarizes the Worst-Case Responses (WCRs) of streams of each class under CQF with preemption. Secondly, this paper analyses the WCR under CQF with preemption. This analysis identifies the factors that influence the transmission latency for streams of each class and proposes several guidelines in parameter configuration under this mechanism combination. Then, this paper develops a scheduler named CQFP scheduler, enabling the computation of the WCR for all streams under CQF with preemption in different network scenarios. Finally, the paper conducts simulations to obtain the WCR under various configurations, validating the guidelines and the results obtained from the CQFP scheduler. This evaluation provides insights into the performance of the combination of CQF and preemption. The results can provide the network designers detailed guidelines in traffic class assignment and parameter configuration under CQF with preemption.
Reinforcement Learning in Optimizing the Electric Vehicle Battery System Coupling with Driving Behaviors
Authors: Altiner Irem , Ou Shiqi (Shawn)
Published: April 2024

Battery Run-down under the Electric Vehicle Operation (BREVO) model is a model that links the driver’s travel pattern to physics-based battery degradation and powertrain energy consumption models. The model simulates the impacts of charging behavior, charging rate, driving patterns, and multiple energy management modules on battery capacity degradation. This study implements reinforcement learning (RL) to the simplified BREVO model to optimize drivers’ decisions on charging such as charging rate, charging time, and charging capacity needed. This is done by a reward function that considers both the driver’s daily travel demands and the minimization of battery degradation over a year. It shows that using appropriate charger type (No Charge, Level 1, Level 2, direct-current Fast Charge [DCFC], extreme Fast Charging [xFC]) with an appropriate charging time can reduce battery degradation and total charging cost at the end of the year while satisfying driver’s daily travel demand. Using the Level 2 charging every day for night charging can reduce the battery capacity by 1.3819 ‰ whereas following the charger type and charging time suggestions of the RL will bring this number down to the level of 0.8037 ‰ over a one-year timespan. This gap between degradation rates gets bigger when one prefers using DC FC or xFC only respectively. Based on their daily travel demands, this RL model provides valuable strategic guidance to drivers to increase the battery lifetime and minimize the total cost of owning an electric vehicle.
Combination of Dissimilar Overlay Materials for Engine Bearing Life Extension
Authors: Haneda Yuma , Kato Kenta , Yasuda Erina , Nogami Akira , Hayashi Masaki
Published: April 2024

Nowadays, Bismuth (Bi) is being applied as an overlay material for engine bearings instead of Lead (Pb) which is an environmentally harmful material. Bi overlay has already been a solid performer in some automotive engine sectors due to its superior load carrying capacity and good robustness characteristic which are necessary to maintain its longevity during the lifetime of engines. The replacement is also seen on relatively larger size engines, such as Trucks and Off-highway heavy duty applications. Basically, these applications require higher power output than passenger cars, and the expected component lifecycle becomes longer. Though Bi has similar material characteristic to traditional Pb, it becomes challenging for the material alone to satisfy these requirements. Polymer overlay is known for its superior anti-wear performance and longer lifetime due to less adhesion against a steel counterpart than metallic materials (included Bi). However, for heavy duty applications where clean operation condition is difficult to maintain, foreign particle can affect the polymer overlay performance.

In this study it has been found longer bearing lifetime under stringent bearing operation condition is achievable by making an optimal combination of Bi and polymer overlays. In general, thicker overlay has simply more margin for material wearing-off and it contributes to longer bearing lifetime. On the other hand, thicker overlay tends to lose anti-fatigue performance at the same time. On Bi and polymer overlay combination, it showed better fatigue resistance than normal thick single Bi overlay. Furthermore, each rig test confirmed that the combination overcomes polymer overlay robustness issue.
Simulation of Self-Piercing Riveting Process in Aluminum Alloy 5754 Using Smoothed Particle Galerkin Method
Authors: Zou Jie , Huang Li , Ren Bo , Zhang Jingyi , JI Yuxiang , Guobi Tan , Zhan Zhenfei
Published: April 2024

Self-piercing riveting (SPR) are one of most important joining approaches in lightweight vehicle design for Body-in-white (BIW) manufacturing. Numerical simulation of the riveting process could significantly boost design efficiency by reducing trial-and-error experiments. The traditional Finite Element Method (FEM) with element erosion is hard to capture the large plastic deformation and complex failure behaviors in the SPR process. The smoothed Particle Galerkin Method (SPG) is a genuine meshless method based on Galerkin's weak form, which uses a novel bond-based failure mechanism to keep the conservation of mass and momentum during the material failure process. This study utilizes a combined FEM and SPG approach to join Aluminum sheet 5754 using a full three-dimensional (3D) model in LS-DYNA/explicit. To mimic the rivet insertion process, the mesh-free SPG method is used to model the material part of the upper and lower sheet where the rivet pierces through, while FEM methods for computational efficiency model the remaining parts. Sensitivity studies are conducted to investigate the impacts of critical model parameters and accurate material properties. This work illustrates that precise material properties and 3D CAE modeling can provide fundamental and insightful information for the SPR process.
Performance of Spark Current Boost System on a Production Engine under Lean-Burn Conditions
Authors: Yu Xiao , Leblanc Simon , Wang Linyan , Zheng Ming
Published: April 2024

In order to improve the fuel economy for future high-efficiency spark ignition engines, the applications of advanced combustion strategies are considered to be beneficial with an overall lean and/or exhaust gas recirculation diluted cylinder charge. Stronger and more reliable ignition sources become more favorable under extreme lean/EGR conditions. Existing research indicates that the frequency of plasma restrikes increases with increased flow velocity and decreased discharge current level, and a higher discharge current can reduce the gap resistance and maintain the stretched plasma for a longer duration under flow conditions. An in-house developed current boost control system provides flexible control of the discharge current level and discharge duration. The current boost ignition system is based on a multi-coil system with a discharge current level of 180mA. In this study, a comparative study has been conducted to investigate the efficacy of multi-coil and multi-core ignition systems on a spark-ignited inline-four cylinder production engine under lean-burn conditions. Both total ignition energy and discharge duration are kept the same. The ignition performance of both strategies has been investigated under various levels of engine loads, including idling (1.1 bar BMEP at 900rpm) and partial engine load (2.6 bar BMEP at 1500rpm) conditions. Using the multi-coil system, the spark advance window could be extended beyond that of the traditional transistor coil ignition. Furthermore, the application of the multi-core ignition system consistently realized a shorter ignition delay period by 2~4°CA regardless of boundary conditions.
Pre-Chamber Combustion System Development for an Ultra-Lean Gasoline Engine
Authors: Du Jiakun , Qi Hongzhong , Chen Hong , Li Yuhuai , Zhan Wenfeng , Jiang Xiaoxiao , Wu Weilong , Zhang Zonglan
Published: April 2024

Amid rising demands for fuel efficiency and emissions reduction, enhancing the thermal efficiency of gasoline engines has become imperative, which requires higher efficiency combustion strategies and integrated optimized design to maximize the work output from fuel. In gasoline engine, both increasing the compression ratio and using lean burn mode improve the ratio of useful work output to the energy input effectively, which resulting in higher thermal efficiency. Although there is limited scope for increasing the compression ratio due to the higher sensitivity to knocking, especially under stoichiometric conditions, reduced sensitivity could be got with leaner mixture fill into cylinder, which can further increase the specific heat ratio and thermal efficiency. However, realizing the efficiency benefits of lean burn in gasoline engines necessitates overcoming critical challenges like ensuring robust ignition process and accelerating burning rates to achieve short, stable combustion durations. To overcome these problems, a kind of pre-chamber ignition concept has been developed, which integrate a dedicate injector and spark plug into one assembly on cylinder head. In this paper, the focus is on the development of such a system and the combustion characteristics on gasoline engine with it.

Primary experimental data is obtained by an ultra-lean single cylinder research gasoline engine equipped with pre-chamber concept. Key structure parameters such as pre-chamber volumetric fraction and jet hole have been comparatively investigated. Experimental study also be performed on a multi-cylinder engine equipped with the same pre-chamber concept in order to verify the maximum Gross-ITE and BTE simultaneously. Results indicated that optimized pre-chamber structure design could make much contribute to the thermal efficiency under ultra-lean mode with lambda up to 2.1. Under this condition, combustion stability was also significantly improved compared to spark ignition with faster and knock-free combustion process. Due to the lower temperature of ultra-lean combustion, Nitrogen Oxides emissions can be significantly reduced. Furthermore, for a given load, it was shown that maximum GITE of 50% on SCE was measured at 2500rpm-11.5bar IMEP together with the maximum BTE of 46.3% on MCE under the same operating condition.
Investigation of Combustion Characteristics of a Fuel Blend Consisting of Methanol and Ignition Improver, Compared to Diesel Fuel and Pure Methanol
Authors: Svensson Magnus , Tuner Martin , Verhelst Sebastian
Published: April 2024

The increasing need to reduce greenhouse gas emissions and shift away from fossil fuels has raised an interest for methanol. Methanol can be produced from renewable sources and can drastically lower soot emissions from compression ignition engines (CI). As a result, research and development efforts have intensified focusing on the use of methanol as a replacement for diesel in CI engines. The issue with methanol lies in the fact that methanol is challenging to ignite through compression alone, particularly at low-load and cold starts conditions. This challenge arises from methanol's high octane number, low heating value, and high heat of vaporization, all of which collectively demand a substantial amount of heat for methanol to ignite through compression. One successful project using methanol is the Fastwater project, where a diesel engine was converted to run on methanol, with 3% ignition improver, and installed in the pilot boat Pilot 120SE, that is running in real world conditions off the east coast of Sweden. The aim of this paper is to evaluate the performance of a fuel blend comprising of 97% methanol and 3% ignition improver (MeOH97), as is utilized in the pilot boat, on a heavy duty CI engine test bench. This evaluation involved a comparison with both diesel fuel and non-blended methanol (MeOH100). The results indicated that, in terms of gross indicated efficiency, MeOH97 is on par with diesel for most load conditions and can potentially even surpass it at higher loads. It is only at the lowest tested load that MeOH97 exhibits a drop in efficiency, although combustion remains stable. Furthermore, the results confirm that the addition of a 3% ignition improver significantly improves the combustibility of methanol, particularly at lower loads. Lastly, the use of methanol leads to a noteworthy reduction in NOx emissions without generating any soot emissions.
Implementing Ordinary Differential Equation Solvers in Rust Programming Language for Modeling Vehicle Powertrain Systems
Authors: Steuteville Robin , Baker Chad
Published: April 2024

Efficient and accurate ordinary differential equation (ODE) solvers are necessary for powertrain and vehicle dynamics modeling. However, current commercial ODE solvers can be financially prohibitive, leading to a need for accessible, effective, open-source ODE solvers designed for powertrain modeling. Rust is a compiled programming language that has the potential to be used for fast and easy-to-use powertrain models, given its exceptional computational performance, robust package ecosystem, and short time required for modelers to become proficient. However, of the three commonly used (>3,000 downloads) packages in Rust with ODE solver capabilities, only one has more than four numerical methods implemented, and none are designed specifically for modeling physical systems. Therefore, the goal of the Differential Equation System Solver (DESS) was to implement accurate ODE solvers in Rust designed for the component-based problems often seen in powertrain modeling. DESS is a text-based software package that provides a flexible framework for building and solving systems of ODEs. This allows DESS to be included as a dependency for automotive powertrain models that require a variety of solvers and solver configurations. Seven explicit ODE solver methods have been implemented in DESS: Euler’s, Heun’s, midpoint, Ralston’s, classic Runge-Kutta, Bogacki-Shampine, and Cash-Karp. These represent five fixed-step methods and two adaptive-step methods. This paper shows that the solver implementations increase accuracy and computational efficiency compared to Euler's method when modeling a system of three thermal masses in Rust. DESS also includes features designed for modeling component-based physical systems. Users can define relationships between nodes in their system, which the package then translates into a system of equations, leading to simpler and more intuitive code. In the case of a three-thermal-mass system, the user can specify node thermal properties (e.g., thermal capacitance), how nodes are interconnected, and thermal conductance between nodes rather than providing a system of equations. The core contribution from this work is an open-source, text-based Rust package with ODE solvers for automotive powertrain modeling to support cost-free, fast, and accurate simulation.
Electric Vehicle Modeling: Advanced Torque Split Analysis across Different Architectures
Authors: Oswald David , Escobar Jacqueline , Wu Guoyuan , Jung Heejung , Barth Matthew
Published: April 2024

The proliferation of electric vehicles (EVs) is resulting in a big transition in the automotive industry, with the goal of reducing greenhouse gas emissions and improving energy efficiency. There are a variety of different architectural configurations and power distribution strategies that can be optimized for drivability performance, all-electric range, and overall efficiency. This paper describes the efforts of the research team in exploring different EV architectures to better understand their impacts on system performance in terms of energy efficiency and vehicle drivability. In search for an ideal powertrain architecture for a shared-use EV, the research team conducted a comprehensive analysis of a various EV architectures (including RWD and AWD) with different motor parameters, considering a spectrum of targeted vehicle technology specifications such as acceleration and braking performance, and fuel economy. To quantify these performance indices, a model-based design approach was utilized, leveraging the EV development tools developed by MATLAB/Simulink and Simscape. Standard driving cycles, e.g., Highway Fuel Economy Driving Schedule (HWFET) and Urban Dynamometer Driving Schedule (UDDS) were utilized to evaluate different EV powertrain architectures and rear/front wheel power splits. The simulation results showed that for the architectures (with respective parameters) investigated in this study, the AWD architectures have higher energy efficiency than the RWD architecture in the range of 5.4 – 37.9%. To further scrutinize performance across a wide spectrum of driving scenarios, we introduced a specialized modal driving profile. This comprehensive profile encompasses a diverse array of modal events, including varying acceleration rates and steady-state speeds, among others. In our analysis, we found that a standard torque split of 50/50 keeps a good balance between energy efficiency and drivability for our target AWD architecture.
Real-Time Deployment Strategies for State of Power Estimation Algorithms
Authors: Schommer Adriano , Araujo Xavier Marcelo , Morrey Denise , Collier Gordana
Published: April 2024

Lithium-ion cells operate under a narrow range of voltage, current, and temperature limits, which requires a battery management system (BMS) to sense, control, and balance the battery pack. The state of power (SOP) estimation is a fundamental algorithm of the BMS. It operates as a dynamic safety limit, preventing rapid ageing and optimizing power delivery. SOP estimation relies on predictive algorithms to determine charge and discharge power limits sustainable within a specified time frame, ensuring the cell design constraints are not violated. This paper explores various approaches for real-time deployment of SOP estimation algorithms for a high-power lithium-ion battery (LIB) with a low-cost microcontroller. The algorithms are based on a root-finding approach and a first-order equivalent circuit model (ECM) of the battery. This paper assesses the practical application of the algorithm with a focus on processor execution time, flash memory and RAM allocation using a processor-in-the-loop (PIL) setup. The case study estimates the maximum power available for regenerative braking at high SOCs and compares predictions with experimental data. More specifically, deployments using single and double-precision floating numbers are compared, alongside different voltage estimation approaches. In addition, the bisection root-finding method is compared to the secant and Brent’s method. The different algorithms tested in this study do not significantly impact memory allocation. In terms of processor load, however, single-precision deployments are significantly more cost-effective than double-precision deployments, with a negligible discrepancy in the predicted output. Finally, the secant root-finding method reduces the execution time by two-thirds while retaining the same level of accuracy when compared to the bisection method.
Electric Motor Noise Reduction with Stator Mounted NVH Insert Ring
Authors: He Song , Tran Xuan , Naismith Gregory , Du Isaac , Patruni Pavan Kumar , Baladhandapani Dhanasekar
Published: April 2024

Electric motor noise mitigation is a challenge in electric vehicles (EVs) due to the lack of engine masking noise. The design of the electric motor mounting configuration to the motor housing has significant impacts on the radiated noise of the drive unit. The stator can be bolted or interference-fit with the housing. A bolted stator creates motor whine and vibration excited by the motor torque ripple at certain torsional resonance frequencies. A stator with interference fit configuration stiffens the motor housing and pushes resonances to a higher frequency range, where masking noise levels are higher at faster vehicle speeds. However, this comes with additional cost and manufacturing process and may impact motor efficiency due to high stress on stators. In this paper, a thin sheet metal NVH ring is developed as a tunable stiffness device between the stator and the motor housing. It is pre-compressed and provides additional torsional rigidity to mitigate torsional excitations. A CAE model is developed to model, analyze, and optimize the NVH ring for the bolted stator configuration. A system-level simulation method is utilized to characterize the interactions of the stator, the NVH ring, and the motor housing as well as the retention force variation of the insert ring due to thermal aspects. The optimized NVH ring provides increased torsional stiffness comparable to an interference fit configuration, which leads to reduced motor noise in the critical low frequency range.
Development of New Motor for Electric Vehicles
Authors: Jozaki Ken , Shibata Ryosuke , Hoshina Hiroshi
Published: April 2024

The world is currently facing environmental issues such as global warming, air pollution, and high energy demand. To mitigate these challenges, the electrification of vehicles is essential as it is effective for efficient fuel utilization and promotion of alternative fuels. The optimal approach for electrification varies across different markets, depending on local energy conditions and current circumstances. Consequently, Toyota has taken the initiative to offer a comprehensive lineup of battery electric vehicles (BEV), hybrid electric vehicles (HEV), plug-in hybrid electric vehicles (PHEV), and fuel cell electric vehicles (FCEV), aiming to provide sustainable solutions tailored to the unique situations and needs of each region.

As part of this effort, Toyota has developed the 5th generation of hybrid electric vehicles. This paper describes the electric motor used in the new Toyota Camry which achieves high torque, high power, low losses, and compact design.

High-strength electromagnetic steel was adopted to allow for magnets to be placed in a novel polygonal arrangement. This new material and design improved the motor torque performance. Increasing the rotor core design flexibility allowed for a reduction of the demagnetizing field. Hence, the adoption of heavy-rare-earth-free magnets in the generator became a reality. In addition, the stator core adopted annealing after the press lamination to facilitate the growth of crystal grains, enabling a reduction in power losses compared to the previous generation motor. A fractional-pitch winding was adopted, and the amount of insulating resin was reduced by using foaming insulating paper that fixes the windings with the stator core. As a result, the end winding height was reduced compared to the previous model. Through these actions, this motor achieves a reduction of 26% in end winding height and an increase of 23% in power density, compared to the previous model.
3D CFD Modeling of an Electric Motor to Predict Spin Losses at Different Temperatures
Authors: Ballani Abhishek , Schlautman Jeff , Srinivasan Chiranth , Ahmed Rayhan
Published: April 2024

With the advent of this new era of electric-driven automobiles, the simulation and virtual digital twin modeling world is now embarking on new sets of challenges. Getting key insights into electric motor behavior has a significant impact on the net output and range of electric vehicles. In this paper, a complete 3D CFD model of an Electric Motor is developed to understand its churning losses at different operating speeds. The simulation study details how the flow field develops inside this electric motor at different operating speeds and oil temperatures. The contributions of the crown and weld endrings, crown and weld end-windings, and airgap to the net churning loss are also analyzed. The oil distribution patterns on the end-windings show the effect of the centrifugal effect in scrapping oil from the inner structures at higher speeds. Also, the effect of the sump height with higher operating speeds are also analyzed. The net churning losses obtained from the simulations are compared to 1D data and close correlations are seen.
Development of Robust Traction Power Inverter Residing in Integrated Power Electronics for Ultium Electric Vehicles
Authors: Nassiri Bavili Arash , Basher Korobi , Chung Sung , Alam Khorshed , Lee Jung-Gi , Choi Hong Goo , Ko Jin-young , Anwar Mohammad
Published: April 2024

General Motors (GM) is working towards a future world of zero crashes, zero emissions and zero congestion. It’s “Ultium” platform has revolutionized electric vehicle drive units to provide versatile yet thrilling driving experience to the customers. Three variants of traction power inverter modules (TPIMs) including a dual channel inverter configuration are designed in collaboration with LG Magna e-Powertrain (LGM). These TPIMs are integrated with other power electronics components inside Integrated power electronics (IPE) to eliminate redundant high voltage connections and increase power density. The developed power module from LGM has used state-of-the art sintering technology and double-sided cooled structure to achieve industry leading performance and reliability. All the components are engineered with high level of integration skills to utilize across TPIM variants. Each component in the design is rigorously analyzed and tested from component to system levels to ensure high reliability, power density and efficiency. All these topics mentioned above are within the scope of this paper.
Mechanical Property Analysis of Hyperbolic Structure: Compression Behavior, Energy Absorption Performance and Geometric Influence
Authors: Wang Zhidong , Wu Chunfu , Ye Guorui , Zhao Yonghong , Ye Baowen , Wang Liangmo , Wang Tao , Zhang Zeming
Published: April 2024

Inspired by the cross-section of a beetle’s elytron, hyperbolic lattice with double-layered feature has received increasing attention in recent years. This paper aims to investigate the compression behavior and energy absorption performance of a truss-based hyperbolic structure. The quasi-static compression simulation for the hyperbolic structure has been performed and validated with a compression test. Through compression simulation and test, the hyperbolic structure proved to show obvious twisting effect. To explore the influences of the geometric parameters in the mechanical properties of hyperbolic structure, this paper has designed 13 cells with varied rotation angle, height, and rod diameter, and investigated the mechanical properties of these configurations. The results show that the rod diameter has the greatest effect on the energy absorption performance of the hyperbolic structure, with a maximum enhancement of 97.5%, while the overall height has the smallest effect with a maximum enhancement of only 0.5% in the most ideal case. This study provides a common reference for exploring the energy-absorbing capabilities of hyperbolic structures.
Development of an Evaluation Method for Fretting Fatigue at the Mating Surface between a Cylinder Block and Main Bearing Cap with Temperature Fluctuations
Authors: Otsuka Yuki
Published: April 2024

Fretting is a phenomenon in which a fatigue crack is initiated by a small relative slip between two objects, resulting in crack propagation and fracture at stresses far below the fatigue limit [1, 2]. Since the mechanism behind fretting is complex and covers multiple disciplines, it is not easy to develop a consistent evaluation method. In the field of engine development, fretting events can also pose an issue due to the complexity of the mechanism [3]. In particular, it has been a challenge to help predict changes in the presence and severity of fretting events, as the engine temperature fluctuates with operating conditions. As one method for evaluating fretting, Sato, et al. have made predictions using analytical models based on the finite element method (FEM) [4, 5]. However, their predictions did not take into account temperature fluctuations in the system, and they were unable to predict events in which the occurrence of fretting fatigue changed with temperature fluctuations.

In this study, first, tests were conducted on an actual engine to examine the effect of temperature on the occurrence of fretting. In addition, the mating surface was observed in detail after the tests. Specifically, the microcracks on the mating surface were measured, and the damaged areas were analyzed for their composition. As a result, it was found that the main factors influencing the occurrence of fretting were the relative slip velocity caused by thermal expansion and the relative slip rate and stress amplitude caused by the crank load. Traditionally, fretting has been evaluated based on the stress amplitude at the mating surface and the relative slip caused by the crank load [4]. In this study, the relative slip caused by thermal expansion due to the difference in thermal expansion coefficients between the two objects was incorporated into the evaluation, making it possible to evaluate fretting while taking the effect of temperature into account. The influence of each factor was quantified using a three-dimensional nonlinear FEM. Simulations included bolt-tightening force, cyclic crankshaft force, and temperature variation. The simulation results were combined with test results from various engine types to develop experimental criteria.
Analysis of Loads Applied to Wheels of Heavy Vehicles and Study on Loosening of Hub Bolts and Nuts
Authors: Hareyama Soichi , Manabe Ken-ichi , Kobayashi Satoshi
Published: April 2024

Heavy vehicles such as construction machinery generally require a large traction force. For this reason, axle components are equipped with a final reduction gear to provide a structure that can generate a large traction force. Basic analysis of vertical load, horizontal load (traction force), centrifugal force, and torsional torque applied to the wheels of heavy vehicles such as construction machinery and industrial vehicles, as well as actual working load analysis during actual operations, were conducted and compiled into a load analysis diagram. The loosening tendency of wheel bolts and nuts that fasten the wheel under actual working load was measured, and the loosening analysis method was presented. The causes of wheel fall-off accidents in heavy trucks, which have recently become a problem, were examined. Wheel bolts are generally tightened by the calibrated wrench method using a torque wrench. The method is susceptible to variations in friction coefficient and tightening torque, and human error affects the tightening torque. Even if the tightening torque (initial clamping force) is insufficient, effective loosening prevention is considered necessary to prevent serious accidents such as wheels falling off. In forklifts, the number of hub bolts is limited due to space limitations, so hub nuts have a spherical or conical alignment structure that allows each nut and bolt to absorb the drive torque and slippage of the bearing surface. In wheel loaders, for example, there is space to install hub bolts, and the clamping force of the bolt sustained slippage of the bearing surface to prevent loosening and fatigue”