bluuebunny/crossref_metadata_2025_split huggingface dataset:
A comparative analysis of YOLOv5 and YOLOv7 object detecting models for speed-limit traffic-sign recognition
Authors: Quang Lam Tran , Truong Thinh Vo , Duong Ly Phi , Nhat Phi Lam , Dang Long Tran 
Published: February 2025

Abstract
Traffic sign recognition is a key element in automatic driver assist systems and autonomous vehicles, significantly improving driver’s comfort and driving safety. The You Only Look Once (YOLO) family of deep-learning-based object-detection algorithm has been widely adopted due to their real-time capabilities and ease of implementation. In this study, we compared the performance of Small-YOLOv5 and Tiny-YOLOv7, two recent variants of the YOLO architecture, on various traffic sign detection benchmarks. Our evaluation focused on three aspects: accuracy, speed/inference time and performance/computational complexity. The two models of YOLOv5 and YOLOv7 were trained with the same data set which consists of 3206 images representative for 7 different speed-limit signs including 50, 60, 70, 80, 90, 100 and 120 km/h, 2 signs of residential area entrance and exit, and 1 sign of all-limit removal. These images were collected in various real-life environmental conditions such as daylight, nighttime, rain, and motion blur from a Raspberry Pi V2 8MP Camera with a resolution of 3280x2464 pixels and a focal length of 3.04 mm. Comparisons were conducted in different scenarios of image quality, distance from camera, and computer resources. In terms of image quality, performance decreased significantly as image quality dropped with YOLOv5, especially in low light, blurry images, and bad weather. Meanwhile, YOLOv7 maintained better performance in various environmental conditions. YOLOv7 was found to be more stable and reliable than YOLOv5 when image quality dropped. In terms of speed/processing time, when running on a system with high resources (such as Google Colab T4), YOLOv7 outperformed YOLOv5 in speed/inference time. On low-end resources (Jetson Nano), YOLOv7 was also slightly better than YOLOv5. Finally, YOLOv7 was able to maintain better performance than YOLOv5 when the subject was at different distances from the camera. The findings of this study suggested that the Tiny-YOLOv7, when combined with a high-level computing platform, could be beneficial for real-time traffic sign recognition.
Research on the ability to generate electric current of the H/Pd(100) system in a fuel cell
Authors: Thai Pham Cong , Hanh Tran Thi Thu 
Published: February 2025

Abstract
Hydrogen fuel cells are being explored as a sustainable energy source. To study the electric current produced in the fuel cell, we used density functional theory (DFT) to simulate the adsorption of hydrogen on the Pd(100) surface in a vacuum environment. Our research focuses on the convergence of the initial k-point selection for the palladium (Pd) system with and without hydrogen atoms. We specifically examined the stability of chemical bonds in the model through the hydrogen adsorption sites. Our simulation results demonstrate that the endothermic reaction of hydrogen atoms on the top site of the Pd surface is the primary reason why it is considered the least favorable site compared to the hollow site and bridge site.
Impact of oxygenated palm-biodiesel on combustion characteristics under various levels of EGR in simulated CI-engine condition
Authors: Tan Vo Chau , Ho Au Hai , Nam Ho Hoa , Mai Tai The 
Published: February 2025

Abstract
Diesel engines, known for their high compression ratios, are extensively used in various sectors including industry, transportation, agriculture, and construction. However, they face significant challenges in meeting strict emission standards. Fossil-derived diesel fuel is cited as a major contributor to serious issues like high environmental pollution, harmful health effects, and the energy crisis. Promoting the development of high technology related to clean fuel is crucial. Exploring the impact of combining high-pressure fuel injection with low oxygen concentration as a form of recirculating part of the exhaust gas back into the engine cylinder (EGR) for oxygenated biodiesel, to enhance fuel efficiency and emission mitigation, presents a promising avenue of research. This work focuses on evaluating the impact of various EGR levels on the combustion behaviors of palm biodiesel (B100) and conventional diesel (B0) under a high fuel injection pressure of 1200 bar and a constant injection time of 2.0 ms in a constant-volume vessel. Compression ignition (CI) engine operating conditions, characterized by an in-cylinder ambient pressure of 43 bar, were investigated under three cases of volumetric oxygen concentrations simulating various EGR levels in diesel engines: no EGR (21% O2), medium EGR (15% O2), and heavy EGR (10% O2). A piezoelectric transducer was utilized to record the combustion pressure, from which combustion characteristics were analyzed. The findings revealed that the ignition delay of B100 is shorter than that of B0 under no EGR conditions and prolongs when reducing the oxygen content to 10%. Increasing the EGR ratio leads to a significant decrease in the integral heat release, the summit of the apparent heat release rate, and peak combustion pressure for both fuel types. Nevertheless, a longer diffusion combustion phase was observed compared to conditions with higher ambient oxygen concentrations. Furthermore, the combustion characteristics of B100 are also lower than those of B0 under test conditions.
Investigation on multi-corners crash-box structure subjected to axial crushing
Authors: Nguyen Hung , Nguyen Dat , Tran Hai , Tran-van Tao 
Published: February 2025

Abstract
This paper investigated the crushing behavior of multi-corner crash-box subjected to quasi-static axial impact loading via FEM numerical simulation and experiments. The effects of the number of welded lines on the welded area and the heat-affected zone, which influence the crushing force, folding process, and energy absorption capacities of multi-corners, are studied. The numerical simulations reveal that adjusting these parameters can significantly influence the crushing behavior and energy absorption characteristics of the multi-corner crash-box. The FEM results also show that using a higher strain-rate material model increases peak and mean force when compared to a low strain-rate material model. In this work, three experiments were conducted to verify FEM model. The experimental results showed great agreement with numerical results in all models of folding collapse in symmetric modes, the crushing force, folding displacement, total energy absorption - EA, specific energy absorption - SEA and the crushing force efficiency - CFE. In conclusion, using the multi-corner crash-box can improve the crashworthiness parameters under axial crushing.
Research in Detection and Evaluation of Green Spaces Using UAV and Artificial Intelligence
Authors: Khoa Ta Dinh , Duy Phan Nguyen Quoc , Hieu Ngo Khanh 
Published: February 2025

Abstract
Numerous efforts have been made to evaluate green areas, ranging from manual methods like tree and leaf counting to more modern approaches such as using satellite imagery. However, these methods have limitations, including high costs, resource-intensive processes, and lack of real-time capabilities. Therefore, our research team developed a method that improves performance and allows for real-time updates. In this study, we utilized an ultra-lightweight unmanned aerial vehicle (UAV) to create a non-image dataset of green vegetation. We trained a deep learning computer vision model using this dataset to recognize and segment green areas. The resulting accuracy was then computed to determine real-world coverage. Although our initial results were not as expected, mostly due to not standardize drone auto flight technique and camera intervals setting, this approach shows promise for addressing the stated problem, and further in-depth research is necessary to enhance the process and outcomes. In our study, we faced several challenges while developing and implementing our approach. One critical aspect was selecting appropriate hyperparameters for training our deep learning model. Let’s delve into some of these considerations: Mean Average Precision (mAP), Confidence Threshold, Overlap (IoU), Training Data, Error Messages during Training and Number of Epochs and Batch Size. Despite these challenges, our preliminary results demonstrate the potential of this approach. Real-time green area assessment using UAVs and deep learning holds promise for environmental monitoring. Further research will refine our methodology and address limitations.
Analcime zeolite beads prepared from mineral clays for CO2 capture application
Authors: Hieu Le Tu , San Phan Vo Vinh , Thang Tran Duc , Phuong Nguyen Thi Truc , Long Nguyen Quang 
Published: February 2025

Abstract
This research focuses on the CO2 capture capacity and physical properties of granulated beads using zeolite ANA synthesized from metakaolin as the raw material, which was obtained from using an alkaline solution for hydrothermal treatment at ambient conditions without any additional sources of silica or alumina. The resulting powder was then granulated with bentonite to improve mechanical strength and sodium alginate to perform a cross-linking reaction with barium chloride. The synthesized zeolite powder ANA and the beads were characterized by X-ray Diffraction (XRD) and Scanning Electron Microscopy (SEM) with Energy-Dispersive Spectroscopy (EDX). The mechanical strength of the beads was also examined. The CO2 adsorption capacity of the beads was investigated using a CO2/N2 mixed gas stream with activation conditions in vacuum environments at 150 °C, 200 °C, and 300 °C, respectively. It was examined that the mechanical strength of the beads gradually declined with rising activation temperature, as a result of sodium alginate degradation. In addition, the highest CO2 adsorption capacity was recorded about 0.46 mmol/g on the sample which was activated at 200 °C.
Aspects in vessel system offsets survey using 3-D laser scanning system
Authors: Le-Dinh Tuan , Tran Hai 
Published: February 2025

Abstract
Recently, the shipbuilding industry has paid more attention to laser scanning technologies due to their ability to quickly and accurately provide and evaluate 3D data. This innovative solution brings benefits as it increases the accuracy of the ship construction and associated production information. This measure is even more advantageous because it significantly shortens the survey time when establishing the positions, and installation angles of mounted equipment and systems onboard ships. The paper describes a vessel system offsets survey that needs to ensure accurate locations and alignment of sensors and equipment on a new building ship before her sea trial. These include the physical vessel offsets and angular rotational offsets of mounted equipment such as GNSS antennae, wind sensors, MGC gyro compass units, range guard sensors, scene scan sensors, etc. The paper also mentions the construction of a reference coordinate system associated with the actual survey on a new building ship, the reference plane, reference points, and offset measurement results of the mounted equipment mentioned above. The measurement results and evaluation of measurement accuracy against the design values show that the application of laser scanners is worthwhile, especially in the shipbuilding industry.
An image-classifying-based diagnostic method applied to electronic fuel injection system for gasoline engine
Authors: Pham Quang T. D. , Huynh Phat Lam , Van Quan Pham , Thai Duong Nguyen , Dang Long Tran 
Published: February 2025

Abstract
The electronic fuel injection (EFI) system significantly governs modern gasoline engine performance. Dirty sensors, weak actuators, broken electric wires, shorted circuits, and mechanical issues are most causes of abnormal system operations. Technicians can use the integrated onboard diagnostic (OBD) function to monitor system behaviour and then apply a standard Symptom-System-Component-Cause (SSCC) diagnostic process to determine what are causing rough idling, hesitate acceleration, excess exhaust gas emissions, and reduced fuel economy. This is a complicated and time-consuming procedure that is prone to human errors, particularly when mechanical causes occur, requiring skilled and experienced technicians. This study aims to demonstrate the feasibility of an automatic diagnostic solution for identifying causes of bad symptoms in EFI systems. Engine live data are collected from the OBD system while the engine is running through a diagnostic engine speed cycle. Live data features are then extracted and visualized as a radar-chart-type diagnostic image, which contains the signatures of normal or abnormal engine operations and can represent a specific cause of failure. By classifying the obtained diagnostic image, the cause of failure is identified. Experiments were conducted with a 4A91 engine, which calculates intake mass air flow from engine speed and intake air density instead of using an air flow meter. Mechanical issues such as cracked intake manifold, evaporative purge valve leak, and weak fuel pump were generated with different degrees of failures. Various pruned versions of the VGG-16 deep learning model were applied to classify diagnostic images thereby can indentify the causes of failure. The results showed that in the case VGG-16 model reduces 2 convolutional layers and 1 dense layer, it is most suitable for this automatic diagnostic application. The proposed diagnostic method can be further improved to detect multi-cause failures as well as predict system degradation trends for early warning and preventive maintenance.
Evaluation of Green Open Space in Creating Child-Friendly Play Spaces in Sumbawa District
Authors: Azzahra T A , Widiyanto D , Widiyastuti D 
Published: February 2025

Abstract
In order to create Child-Friendly Play Areas as one of the requirements for a Child-Friendly District, several green open spaces in Sumbawa District have been designed as play areas to meet the play needs of children in this region. This research uses a quantitative method, utilizing both secondary and primary data relevant to the study. Data collection involved literature studies, field observations and interviews. Quantitative data processing was conducted using scoring techniques to evaluate green open spaces as children’s play areas, categorizing them into “good”, “adequate”, or “poor” groups. The study identified eight green open spaces that serve as Children Play Areas. The assessment revealed that these eight green open spaces in Sumbawa District vary in type and are not limited to parks. The research findings show that Mangga Park has the highest total score, making it the only green open space categorized as “good” play area. The development strategy prioritizes Mangga Park as the main focus for developing Child-Friendly Play Spaces (RBRA) in Sumbawa District. Apart from that, revitalizing facilities and accessibility in other green open spaces, as well as prioritizing their development by considering hazards and disaster risks, is also crucial in implementing development of green open spaces.
Petrogenetic relationship of pre-caldera and caldera-forming magmas from Maninjau volcano, West Sumatera, Indonesia
Authors: Kaneda Yasuaki , Suhendro Indranova , Shibata Shohei , Naen Gabriela Nogo Retnaningtyas Bunga , Aka Festus Tongwa , Hasegawa Takeshi 
Published: February 2025

Abstract
The 220–250 km3 (VEI 7) caldera-forming eruption of Maninjau (West Sumatra, Indonesia) in 52 ±3 ka played a major role for changing the landscape in the Padang Volcanic Field. Besides forming thick and widespread ignimbrite plateau (especially in the vicinity of Bukttinggi), the eruption successfully exposed the stratigraphy of pre-caldera rocks which predominantly constructed of lava (hereafter referred to as somma lava). Since our knowledge regarding the relationship between the pre-caldera somma lavas and silicic caldera-forming activity is lacking, we aimed to study the petrological characteristics of these eruptive materials. Somma lavas are mostly classified as medium-K andesite to dacite (SiO2 = 57–64 wt.%) except for one rhyolitic sample (SiO2 = 77 wt.%). Although whole-rock chemistry of somma lavas largely shows coherent compositional trends that a priori suggest mixing with caldera-forming magmas, there are considerable compositional gaps between them on some SiO2 against incompatible-element (e.g., Sr and Zr) diagrams. Rayleigh fractionation models suggest that it is difficult to generate the caldera-forming silicic magma by differentiation of somma lava magma. Considering the incoherences of petrological and chronological features between Maninjau somma lavas and ignimbrites, we suggest that the caldera-forming large silicic magma evolved as an independent system after the termination of pre-caldera magmatism.
Landscape archaeology as a key concept of cultural resources management in Indonesia
Authors: Putranto A , Suharyadi R , Haryono E , Muta’ali L 
Published: February 2025

Abstract
Archaeological practice adheres to the principle that the cultural resources associated with human activity in the past, including those in Indonesia, constitute the collective heritage of humanity. The concept of cultural heritage is, in fact, inextricably linked to the concept of national identity. The remains may be classified according to several different categories. These comprise a variety of categories, including objects, buildings, structures, sites, and cultural heritage areas. Consequently, the proper management of these resources is of great importance to ensure their preservation for future generations. An interdisciplinary approach is required for the strategic management of cultural resources, in which the valuable contributions of relevant academic disciplines need to be drawn upon. This paper puts forward a conceptual idea derived from a review of the literature relating to the theory and concepts relevant to landscape archaeology. It can be very effective to combine VOSviewer with the PICOT method (Population, Intervention, Comparison, Outcome, Time) to perform gap analysis. The theoretical and conceptual framework presented here was inspired by the discipline of geography, particularly landscape ecology, and will be contrasted with existing concepts. This paper proposes fresh conceptual approaches to managing cultural resources. These approaches represent a significant departure from the conventional conceptual framework that has previously informed this field. The issue of cultural resource management in Indonesia has remained constant for some time, with an emphasis on material cultural legacy and a lack of understanding of other factors in its immediate proximity. The fundamental purpose of this study is to provide a conceptual notion based on landscape archaeology, drawing on the interconnectedness of theory and concept with landscape ecology, to provide the best answer for cultural resource management in Indonesia.
Analysis of Water Quality Dynamics of Sentarum Lake, Indonesia, with Water Index Application and Water Parameter Algorithm Methods Using Google Earth Engine
Authors: Rifai M , Harintaka  
Published: February 2025

Abstract
Water quality is one of the main issues with lake degradation in Indonesia. Limited water quality data due to a lack of funding makes lake management in Indonesia difficult. The use of remote sensing technology has enormous potential as a source of data provision to obtain water quality information. We monitored Sentarum Lake in West Kalimantan, Indonesia, from 2019 to 2024 using open-access Sentinel-2 remote sensing data on the Google Earth Engine cloud computing platform. In this study, we combined Sentinel-2 Harmonized with the cloud score+ algorithm to produce cloud-free images of the study location. This paper used the Application Water Index and water parameter algorithms to analyze water quality. Using the Modified Normalized Difference Water Index (MNDWI), water area segmentation enhances open water features while efficiently suppressing and eliminating non-water area information. To estimate chlorophyll-a (Chl-a), we proposed the Normalized Difference Chlorophyll Index (NDCI) and an algorithm. Calculate total suspended solids (TSS) concentration using the Normalized Difference Texture Index (NDTI) and an algorithm. The study’s findings show that Sentarum Lake’s water quality is generally in excellent condition, with yearly averages of Chl-a and TSS fluctuating. This lake categorizes the lake as seasonal based on its stable condition. This estimate will provide lake managers and policymakers with critical information.
Flood Vulnerability Analysis in Banyumas Regency, Indonesia
Authors: Hermawan Hannan Revi , Azizah Aldina Noer , Widyaningsih Denok , Andhika Dimas , Karima Faricha Nur , Pahmi Iskandar Kesuma , Nataris Nur Shabrina Lintang , Viantami Srani Riska , Hizbaron Dyah Rahmawati 
Published: February 2025

Abstract
Banyumas Regency, Indonesia, is often hit by recurrent annual floods that affect the local population’s physical environments and social conditions. Therefore, a vulnerability analysis is needed to determine potential damage, loss of property, and number of people affected in the wake of floods. The research objectives were to identify and map flood vulnerability in the regency, both in total and by component (social, physical, and environmental). Geographic Information System (GIS) approaches were used to overlay, score, and weigh components and their variables. In the vulnerability assessment, three weighting scenarios were observed: weighting based on Regulation of the Head of the National Disaster Management Agency (NDMA) No. 2 of 2012, equal weighting, and dominance-based weighting. Results indicate that the NDMA scenario produced the broadest and most widely distributed high-vulnerability areas. The other two scenarios showed a comparable spatial distribution pattern with the locus of high total vulnerability on the Serayu River banks in the middle (the entire Purwokerto Municipality) and southern parts of the regency (Banyumas and Kebasen Districts). This can be linked to many settlement areas and their supporting facilities in Banyumas and Purwokerto that are traversed by this major river. As for Kebasen, it lies in a basin abutted by the lower reach of Halang Formation Hills, with the river meandering through its densely populated settlements.