bluuebunny/crossref_metadata_2025 huggingface dataset:
A Perceptual Assessment of the Physical Environment in Teaching Buildings and Its Influence on Students’ Mental Well-Being
Authors: Wen Qiang , Zhou Qiang , Ye Huiyao , Guo Qinghai , Shan Jingwen , Huang Zhonghui
Published: June 2024

Numerous studies have examined the impact of the built environment on mental health, yet there remains an underexplored area concerning how microenvironments within educational buildings affect students’ mental well-being from a physical environment standpoint. This paper fills this gap by utilizing data from 440 valid questionnaires to develop regression models that assess students’ perceptions of physical environment factors in college teaching buildings and their impact on anxiety likelihood. This study examined the physical environment of the teaching building’s interior, courtyard, and semi-outdoor areas. Findings indicate that students’ perceptions of specific physical environment factors—such as classroom ventilation (p < 0.01, OR = 0.330), lighting (p < 0.01, OR = 0.444), noise conditions (p < 0.01, OR = 0.415), courtyard thermal comfort (p < 0.01, OR = 0.504), and the views from semi-outdoor areas (p < 0.01, OR = 2.779)—significantly influence the likelihood of experiencing anxiety. Optimal physical conditions are linked to reduced student anxiety. The suitability of the physical environment of teaching buildings is interrelated, and it is urgently necessary to address issues related to unsuitable lighting in window areas of classrooms, as well as problems with ventilation, lighting, and noise caused by the corridor layout within teaching buildings. These insights are crucial for the design and renovation of academic buildings to enhance students’ mental well-being.
Study on Mechanical Properties and Constitutive Relationship of Steel Fiber-Reinforced Coal Gangue Concrete after High Temperature
Authors: Ge Zhenzhuo , Cai Bin
Published: June 2024

In this paper, steel fiber coal gangue concrete is examined for its fire resistance, high strength, and stability, aiming to achieve both green sustainability and resistance to elevated temperatures. We conducted tests on concrete specimens with varying coal gangue aggregate volume replacement rates (0%, 20%, 40%, 60%) and steel fiber volume contents (0%, 0.5%, 1.0%, 1.5%) to assess their post-high-temperature mechanical properties. These tests were performed at five temperature levels: 20 °C, 200 °C, 400 °C, 600 °C, and 800 °C. The focus was on analyzing the residual mechanical properties and constitutive relationship of the steel fiber coal gangue concrete after exposure to high temperatures. The findings indicate that as the temperature rises, the compressive strength, split tensile strength, and modulus of elasticity of the steel fiber coal gangue concrete specimens undergo varying degrees of reduction. However, the peak strain and ultimate strain increase gradually. The incorporation of steel fibers enhances the mechanical properties of the coal gangue concrete, resulting in improvements in the elastic modulus and peak strain, both before and after exposure to high temperatures. Furthermore, the established constitutive relationship for steel fiber coal gangue concrete after high temperatures, derived from calculations and validated with experimental data, provides a more accurate representation of the entire damage process under uniaxial compressive loading at elevated temperatures.
An Investigation into the Causes of Payment Delays and Deliberate Delay Tactics in Public Construction Projects in Saudi Arabia
Authors: Bageis Abdulrahman Salem
Published: June 2024

Many scientific publications pointed out delays in the progress of payments by owners as one of the top direct causes of project delays and disputes. This research investigates the causes of payment delays and explores deliberate delay tactics and their reasons within Saudi Arabian public construction projects. This research employs a robust mixed methodology, an extensive literature review, and preliminary semi-structured interviews to identify the causes of payment delays and possible tactics and reasons for deliberate delays or procrastinated payment. Subsequently, a questionnaire survey is distributed among experienced personnel. The survey aims to verify the results of the first phase, assess occurrence rates of the causes of payment delays, study tactical forms used by parties to delay payment, and identify reasons for such practices. The findings of the study reveal that the contractual issues group has the highest score for occurring, deliberate disruptions occur although they are not prevalent, tactics to deliberate delays exist and are practiced, and all the possible forms of deliberate delays under investigation and reasons for deliberate delays are confirmed valid. This study provides valuable insights for businesses and policymakers seeking to comprehend the issue of payment delays in Saudi Arabian public construction projects.
Research on the Spatial Structure of the Beijing–Tianjin–Hebei Urban Agglomeration Based on POI and Impervious Surface Coverage
Authors: Zhang Tiange , Zhu Xia , Liu Yuanping , Jia Cui , Bai Huimin
Published: June 2024

Exploring urban spatial structures through spatial coupling analysis methods is an important method to provide theoretical support for the construction of sustainable urban structures. In order to make up for the neglect of POI species differences in previous studies, information entropy was introduced to calculate POI confusion, and a comprehensive POI index was constructed by combining kernel density and the entropy weight method; impervious surface coverage was extracted based on land cover data. The spatial distribution of the Beijing–Tianjin–Hebei urban agglomeration and some typical cities was analyzed by coupling two types of data using the dual-factor mapping method. The research indicates the following: (1). The spatial distribution of the two sets of data in the Beijing–Tianjin–Hebei region is highly consistent, indicating a state of high spatial coupling; Beijing has the highest proportion of coupling in the same region at the city level (73.39%). (2). The areas with different coupling of the two types of data are mainly distributed in the urban fringe areas transitioning from the city center to the suburbs, as well as in large-scale areas with single functionality such as airports, scenic spots, and ports. This study shows that analysis combining the POI comprehensive index and impervious surface coverage can effectively characterize urban spatial structure characteristics, providing a new perspective for the study of the spatial structure of the Beijing–Tianjin–Hebei urban agglomeration. It is of great significance for a deeper understanding of the laws of urban agglomeration spatial structures and guiding the coordinated development of the Beijing–Tianjin–Hebei urban agglomeration.
User Preferences on the Application of Wooden Wall Coverings in Interiors Made of Oak Veneer Residue
Authors: Mamić Domagoj , Domljan Danijela
Published: June 2024

Guided by the principles of visual perception and basic design, this research was conducted to examine users’ preferences on how they perceive natural unique wood phenomena of Pedunculate Slavonian Oak veneers (Quercus robur L.) such as color changes, wood rays, sapwood, and knots, which in the production and technical sense represent defects and wood residue, but could be used in the design of sustainable and ecological wall decorations. The goal was to detect samples with the most positive attributes and to observe their connection with activities and functional space if they are viewed as wall coverings in the interior. The results confirm that discoloration and wood rays are considered the most harmonious (“prettiest”) decors. Discoloration is associated with quiet cognitive or medium-intensity activity that can be used in libraries, hotel rooms, and classrooms. Wood rays are connected with very quiet activity in ambulance waiting rooms or religious buildings and museums. Knot decors are considered the most natural and are recommended for interiors with very or medium-intensive activities such as restaurants, cafes, and hotel receptions, but attention should be paid to the way the wall decors are arranged on the walls. Sapwood–hardwood decors are the subject of further research and improvement concerning the relationship between the dark and light parts of the veneer. In conclusion, the results provide useful guidelines for manufacturers with a large veneer residue in production and who want to design decorative wall panels, as well as for designers and architects designing interiors for a specific purpose and function where certain user behavior and psychological stimulation are desired.
Development of a Site Information Classification Model and a Similar-Site Accident Retrieval Model for Construction Using the KLUE-BERT Model
Authors: Shin Seung-Hyeon , Won Jeong-Hun , Jeong Hyeon-Ji , Kang Min-Guk
Published: June 2024

Before starting any construction work, providing workers with awareness about past similar accident cases is effective in preventing mishaps. Based on construction accident reports, this study developed two models to identify past accidents at sites with similar site information. The site information includes 16 parameters, such as type of work, type of accident, the work in which the accident occurred, weather conditions, contract conditions, type of work, etc. The first model, the site information classification model, uses named entity recognition tasks to classify site information, which is extracted from accident reports. The second model, the similar-site accident retrieval model, which finds the most similar accidents that occurred in the past from input site information, uses a semantic textual similarity task to match the classified information with it. A total of 17,707 accident reports from South Korean construction sites were found; these models were trained to use Korean Language Understanding Evaluation–Bidirectional Encoder Representations from Transformers (KLUE-BERT) for processing. The first model achieved an average accuracy of 0.928, and the second model was precisely matched, with a mean cosine similarity score exceeding 0.90. These models could identify and provide workers with similar past accidents, enabling proactive safety measures, such as site-specific hazard identification and worker education, thereby allowing recognition of construction safety risks before starting work. By integrating site information with historical data, the models offer an effective approach to improving construction safety.
Principles and Clinical Application of Free-Style Capillary Perforator-Based Flap for Coverage of Facial Skin Cancer Defects
Authors: Shim Hyung-Sup , Ryoo Hyun-Jung , Choi Jae-Seon , Park Ji-Ah , Kim Youn-Hwan
Published: June 2024

This study introduces a free-style perforator based island flap (PBIF) for the reconstruction of skin defects. From March 2012 to December 2022, a retrospective investigation was conducted on patients who underwent reconstruction for facial defects due to skin cancer. Data on the patients’ gender, age, anesthesia method, diagnosis, defect location, flap size, complications, and follow-up periods were collected. There are several principles for designing the PBIF: finger-pinching method, alignment with the direction of wrinkles, the smaller width and longer length of the flap, and proximal attachment to the muscle. A total of 32 patients were included, with an average age of 63.6 years. Surgeries were performed in various regions, such as the infraorbital area, nose, cheek, philtrum, and the anterior/posterior/inferior auricular regions, with an average flap size of 7.63 cm2. There were no complications, such as venous congestion or vascular insufficiency in the skin flaps, although one case required revisional closure due to flap disruption. The PBIF is a useful and effective method for the restoration of facial defects. This method can provide simple yet aesthetically satisfying results, showing stable outcomes without complex surgeries or complications. This study indicates the potential for this method to be more widely employed in reconstructive surgeries in the future.
Genome-Wide DNA Methylation Profiling as a Prognostic Marker in Pituitary Adenomas—A Pilot Study
Authors: Møller Morten Winkler , Andersen Marianne Skovsager , Halle Bo , Pedersen Christian Bonde , Boldt Henning Bünsow , Tan Qihua , Jurmeister Philipp Sebastian , Herrgott Grayson A. , Castro Ana Valeria , Petersen Jeanette K. , Poulsen Frantz Rom
Published: June 2024

Background: The prediction of the regrowth potential of pituitary adenomas after surgery is challenging. The genome-wide DNA methylation profiling of pituitary adenomas may separate adenomas into distinct methylation classes corresponding to histology-based subtypes. Specific genes and differentially methylated probes involving regrowth have been proposed, but no study has linked this epigenetic variance with regrowth potential and the clinical heterogeneity of nonfunctioning pituitary adenomas. This study aimed to investigate whether DNA methylation profiling can be useful as a clinical prognostic marker. Methods: A DNA methylation analysis by Illumina’s MethylationEPIC array was performed on 54 pituitary macroadenomas from patients who underwent transsphenoidal surgery during 2007–2017. Twelve patients were excluded due to an incomplete postoperative follow-up, degenerated biobank-stored tissue, or low DNA methylation quality. For the quantitative measurement of the tumor regrowth rate, we conducted a 3D volumetric analysis of tumor remnant volume via annual magnetic resonance imaging. A linear mixed effects model was used to examine whether different DNA methylation clusters had different regrowth patterns. Results: The DNA methylation profiling of 42 tissue samples showed robust DNA methylation clusters, comparable with previous findings. The subgroup of 33 nonfunctioning pituitary adenomas of an SF1-lineage showed five subclusters with an approximately unbiased score of 86%. There were no overall statistically significant differences when comparing hazard ratios for regrowth of 100%, 50%, or 0%. Despite this, plots of correlated survival estimates suggested higher regrowth rates for some clusters. The mixed effects model of accumulated regrowth similarly showed tendencies toward an association between specific DNA methylation clusters and regrowth potential. Conclusion: The DNA methylation profiling of nonfunctioning pituitary adenomas may potentially identify adenomas with increased growth and recurrence potential. Larger validation studies are needed to confirm the findings from this explorative pilot study.
Navigating Fertility Preservation Options in Gynecological Cancers: A Comprehensive Review
Authors: Chitoran Elena , Rotaru Vlad , Mitroiu Madalina-Nicoleta , Durdu Cristiana-Elena , Bohiltea Roxana-Elena , Ionescu Sinziana-Octavia , Gelal Aisa , Cirimbei Ciprian , Alecu Mihnea , Simion Laurentiu
Published: June 2024

(1) Background: Currently, an increasing number of women postpone pregnancy beyond the age of 35. Gynecological cancers affect a significant proportion of women of reproductive age, necessitating the development of fertility preservation methods to fulfill family planning. Consequently, providing treatment options that preserve fertility in women diagnosed with gynecological cancers has become a crucial component of care for survivors. (2) Methods: We conducted an extensive search of relevant scientific publications in PubMed and Embase databases and performed a narrative review, including high-quality peer-reviewed research on fertility after being treated for gynecologic cancers, reporting pregnancy rates, birth rates, and pregnancy outcomes in cancer survivors as well as therapeutic options which partially preserve fertility and methods for obtaining a pregnancy in survivors. (3) Discussion: The medicine practiced today is focused on both treating the neoplasm and preserving the quality of life of the patients, with fertility preservation being an important element of this quality. This leads to an improved quality of life, allowing these women to become mothers even in the seemingly adverse circumstances posed by such a pathology. However, although there are guidelines on female fertility preservation in the context of neoplasms, an analysis shows that physicians do not routinely consider it and do not discuss these options with their patients. (4) Conclusions: Advancements in medicine have led to a better understanding and management of gynecological neoplasms, resulting in increased survival rates. Once the battle against these neoplasms is won, the issue of preserving the quality of life for these women arises, with fertility preservation being an important aspect for women who have not yet fulfilled their family planning desires at the time of diagnosis. It is important for patients to be informed about the available options for fertility preservation and to be encouraged to make informed decisions in collaboration with their medical team. Standardized recommendations for onco-fertility into guidelines should be taken into consideration in the future.
DPEP Inhibits Cancer Cell Glucose Uptake, Glycolysis and Survival by Upregulating Tumor Suppressor TXNIP
Authors: Zhou Qing , Nguyen Trang Thi Thu , Mun Jeong-Yeon , Siegelin Markus D. , Greene Lloyd A.
Published: June 2024

We have designed cell-penetrating peptides that target the leucine zipper transcription factors ATF5, CEBPB and CEBPD and that promote apoptotic death of a wide range of cancer cell types, but not normal cells, in vitro and in vivo. Though such peptides have the potential for clinical application, their mechanisms of action are not fully understood. Here, we show that one such peptide, Dpep, compromises glucose uptake and glycolysis in a cell context-dependent manner (in about two-thirds of cancer lines assessed). These actions are dependent on induction of tumor suppressor TXNIP (thioredoxin-interacting protein) mRNA and protein. Knockdown studies show that TXNIP significantly contributes to apoptotic death in those cancer cells in which it is induced by Dpep. The metabolic actions of Dpep on glycolysis led us to explore combinations of Dpep with clinically approved drugs metformin and atovaquone that inhibit oxidative phosphorylation and that are in trials for cancer treatment. Dpep showed additive to synergistic activities in all lines tested. In summary, we find that Dpep induces TXNIP in a cell context-dependent manner that in turn suppresses glucose uptake and glycolysis and contributes to apoptotic death of a range of cancer cells.
A Survey on Complexity Measures for Pseudo-Random Sequences
Authors: Li Chunlei
Published: June 2024

Since the introduction of the Kolmogorov complexity of binary sequences in the 1960s, there have been significant advancements on the topic of complexity measures for randomness assessment, which are of fundamental importance in theoretical computer science and of practical interest in cryptography. This survey reviews notable research from the past four decades on the linear, quadratic and maximum-order complexities of pseudo-random sequences, and their relations with Lempel–Ziv complexity, expansion complexity, 2-adic complexity and correlation measures.
Disentangling the Effects of Climate and Land Uses on Small Mammals in Agroecosystems of NE Spain
Authors: Torre Ignasi , Requejo Andrés , Arrizabalaga Antoni , Baucells Jordi
Published: June 2024

We analyzed the two main drivers (climate and land uses) shaping the composition of small mammal communities at 16 localities situated in the confluence of the Mediterranean and Eurosiberian regions (Barcelona, Spain). The study area represents a land use and land cover gradient showing urbanization and crop intensification in the lowlands and forest encroachment in mountain areas. We identified 2458 small mammal individuals of 12 different species from barn owl (Tyto alba) pellets. Three open-land species (Microtus duodecimcostatus, Crocidura russula, and Mus spretus) and one forest/generalist species (Apodemus sylvaticus) were dominant in the diet, accounting for 93% of prey. In order to disentangle the effects of both main drivers on the small mammal community, we used partial constrained ordination techniques, which allowed us to determine the pure effects (and shared effects) of the environmental factors. Land use predictors explained 33.4% of the variance (mostly crops), followed by 23.4% of the variance explained by the geo-climatic variables (mostly rainfall), and an additional 24.8% of the variance was shared by both groups of predictors, totaling 81.6% of environmental variance. The remaining 18.4% of variance was unexplained by environmental matrices. This pattern was consistent with expected associations of species and biotic influences at small spatial scales and highlighted that the number of species increased from the crops in the lowlands towards the highlands covered by deciduous and coniferous forests.
The Role of Endoscopic Ultrasonography (EUS) in Metastatic Tumors in the Pancreas: 10 Years of Experience from a Single High-Volume Center
Authors: Aversano Alessandro , Lissandrini Laura , Macor Daniele , Carbone Martina , Cassarano Sara , Marino Marco , Giuffrè Mauro , De Pellegrin Alessandro , Terrosu Giovanni , Berretti Debora
Published: June 2024

Background: Metastatic pancreatic lesions (MPLs) are relatively uncommon, constituting 2 to 5% of all pancreatic tumors. They often manifest as solitary lesions without distinct clinical symptoms, usually identified incidentally during radiologic imaging for the surveillance of prior malignancies. Differentiating these lesions from primary pancreatic tumors presents a significant challenge due to their nonspecific presentation. Methods: We aimed to prospectively assess the effectiveness of endoscopic ultrasound (EUS) and EUS-guided fine needle aspiration/biopsy (EUS-FNA/B) in diagnosing MPLs in a carefully selected cohort of patients presenting with pancreatic masses. Additionally, we sought to examine the relevance of specific EUS findings in supporting the initial diagnosis of MPLs and their agreement with the definitive cytological diagnosis. This study retrospectively analyzed data from 41 patients diagnosed with MPLs between 2013 and 2023, focusing on their clinical and pathological characteristics, the echogenic features of the pancreatic lesions, and the techniques used for tissue acquisition. Results: The incidence of MPLs in our cohort was 3.53%, with the most frequent primary tumors originating in the kidney (43.90%), colorectum (9.76%), lung (9.76%), lymphoma (9.76%), and breast (4.88%). MPLs typically presented as hypoechoic, oval-shaped lesions with well-defined borders and were predominantly hypervascular. Interestingly, 68.29% of the cases were discovered incidentally during follow-up of the primary tumors, while the involvement of the common bile duct was uncommon (19.51%). Conclusions: EUS and EUS-FNA/B have been validated as valuable diagnostic tools for identifying MPLs. While our findings are promising, further multicenter studies are necessary to corroborate these results and elucidate the predictive value of specific EUS characteristics in determining the metastatic origin of pancreatic lesions.
Distributed Finite-Time ESO-Based Consensus Control for Multiple Fixed-Wing UAVs Subjected to External Disturbances
Authors: Yu Yang , Chen Jianlin , Zheng Zixuan , Yuan Jianping
Published: June 2024

This paper puts forward a coordinated formation control scheme for multiple fixed-wing unmanned aerial vehicle (UAV) systems with external nonlinear disturbances including not only the drag force and uncertain lateral force, but also the drag, lift, and lateral forces caused by wake vortices. A novel distributed finite-time extended state observer is designed to estimate both the unmeasurable states and uncertain external nonlinear disturbances of each fixed-wing UAV. In particular, an event-triggered mechanism is employed to reduce the burden of communication networks among multiple fixed-wing UAVs. Meanwhile, an inter-trigger output predictor, replacing the classic zero-order holder, is adopted to obtain cooperative errors between two consecutive triggering moments. Furthermore, a composite distributed controller is proposed to mitigate uncertain disturbances, enabling the coordinated formation flying of multiple fixed-wing UAVs.Finally, two illustrative simulation scenarios are discussed to verify the performance of the presented coordinated formation control scheme.
Multi-Objective Deployment of UAVs for Multi-Hop FANET: UAV-Assisted Emergency Vehicular Network
Authors: Li Haoran , Hao Xiaoyao , Wen Juan , Liu Fangyuan , Zhang Yiling
Published: June 2024

In the event of a sudden natural disaster, the damaged communication infrastructure cannot provide a necessary network service for vehicles. Unfortunately, this is the critical moment when the occupants of trapped vehicles need to urgently use the vehicular network’s emergency service. How to efficiently connect the trapped vehicle to the base station is the challenge facing the emergency vehicular network. To address this challenge, this study proposes a UAV-assisted multi-objective and multi-hop ad hoc network (UMMVN) that can be used as an emergency vehicular network. Firstly, it presents an integrated design of a search system to find a trapped vehicle, the communication relay, and the networking, which significantly decreases the UAV’s networking time cost. Secondly, it presents a multi-objective search for a trapped vehicle and navigates UAVs along multiple paths to different objectives. Thirdly, it presents an optimal branching node strategy that allows the adequate use of the overlapping paths to multiple targets, which decreases the networking cost within the limited communication and searching range. The numerical experiments illustrate that the UMMVN performs better than other state-of-the-art networking methods.
An Assessment of the Effectiveness and Scale of Tax Expenditures to Support Investments and Priority Sectors in G20 Countries
Authors: Demidova Svetlana , Tyurina Yuliya , Kulachinskaya Anastasia , Buzdalina Olga , Ilin Igor V. , Razletovskaia Victoriya , Misbakhova Chulpan A.
Published: June 2024

Tax expenditure management is one of the tools for conducting responsible fiscal policy. Unlike direct expenditures, tax expenditures do not consume resources, but allow the achievement of certain social and economic goals. The purpose of this study is to test the hypothesis of the expediency of using the mechanism of tax expenditures to influence investment activities and the development of priority sectors of the economy. The object of this study was a sample of nine countries of the G-20 group, whose reports provided data on the share of tax expenditures related to investment support and stimulating the development of priority sectors of the economy. The practice of generating reports on tax expenditures is quite common in developed countries, but there are several limitations for cross-country comparison: national characteristics of fiscal elements, and the level of openness and transparency of data on tax expenditures. The scale of using tax expenditures is determined by the multidimensional average method; countries are rated according to the value of the integral indicator. The scale of tax breaks determines the position in the ranking. The effectiveness of using tax breaks is assessed through the coefficient of increase in investment and the coefficient of increase in industrial production. The assessment results show whether economic indicators are outpacing the growth rate of tax benefits and preferences. A study of panel data revealed the average degree of influence of the total amount of tax expenditures on the dynamics of capital investments. The allocation of a target group of tax expenditures related to investment support showed a weak degree of influence on the dynamics of capital investment volumes. The results obtained can be explained by the fact that the allocation of a target group of tax expenditures may not reflect the full range of tax benefits provided to support investments, which is due to the peculiarities of the system of accounting and assessment of tax expenditures in a particular country. In addition, the contribution of tax expenditures may be insignificant if direct forms of support prevail.
A Three-Port DC-DC Converter with Partial Power Regulation for a Photovoltaic Generator Integrated with Energy Storage
Authors: Ye Donghui , Martinez Sergio
Published: June 2024

A novel integrated DC-DC converter is proposed for the first stage of two-stage grid connected photovoltaic (PV) systems with energy storage systems. The proposed three-port converter (TPC) consists of a buck–boost converter, interposed between the battery storage system and the DC-AC inverter, in series with PV modules. The buck–boost converter in the proposed TPC is utilized for maximum power point tracking by regulating two power switches. The output power of the proposed converter is regulated by controlling the DC-AC converter. During the battery-charging mode, partial power regulation is employed with a direct power flow path (the series-connection of the PV panel, the battery and the output). As resistances in this path are almost negligible, the power conversion efficiency is higher than existing topologies. During battery-discharging mode, the power conversion is processed through a buck–boost converter with only two active power switches and one inductor. With fewer components, higher power conversion efficiency is also achieved. The circuit operation and analysis are presented in detail. To illustrate the simplicity of the converter control, the performance of the converter is tested with a straightforward maximum power point tracking on a PV system with battery cells. Simulation and experimental tests are carried out to demonstrate circuit operation and power conversion efficiency.
All-Optical 4-Bit Parity Generator and Checker Utilizing Carrier Reservoir Semiconductor Optical Amplifiers
Authors: Kotb Amer , Zoiros Kyriakos E. , Guo Chunlei , Chen Wei
Published: June 2024

This research explores the forefront of all-optical data processing systems through the utilization of carrier reservoir semiconductor optical amplifiers (CR-SOAs). Recent advancements have showcased the successful design and implementation of CR-SOA-based combinational systems, incorporating pivotal elements like half adders, half subtractors, digital-to-analog converters, latches, header recognition, and header processors. These breakthroughs signify a significant stride towards the realization of faster and more efficient optical logic systems. This study delves into the distinctive characteristics of CR-SOA-based Mach–Zehnder interferometer (MZI) functioning as an XOR gate, emphasizing their transformative potential in information processing. By integrating them into the architecture of an all-optical 4-bit parity generator and checker, the research underscores the practicality of CR-SOA technology in all-optical processing, offering unprecedented speeds and facilitating enhanced data processing capabilities at a remarkable speed of 120 Gb/s return-to-zero pulses. In evaluating the performance of the proposed scheme, the research employs the quality factor metric. This assessment not only yields quantitative insights into the efficacy of CR-SOA-based logic systems but also establishes a critical benchmark for their practical implementation. The study further explores the impact of key data signals and CR-SOA parameters on this metric. The outcomes demonstrate the ability of the CR-SOA-based MZI to cascade and form more intricate logic circuits, thereby highlighting the versatility and potential of this innovative approach in advancing the landscape of all-optical data processing.
Surveying Racial Bias in Facial Recognition: Balancing Datasets and Algorithmic Enhancements
Authors: Sumsion Andrew , Torrie Shad , Lee Dah-Jye , Sun Zheng
Published: June 2024

Facial recognition systems frequently exhibit high accuracies when evaluated on standard test datasets. However, their performance tends to degrade significantly when confronted with more challenging tests, particularly involving specific racial categories. To measure this inconsistency, many have created racially aware datasets to evaluate facial recognition algorithms. This paper analyzes facial recognition datasets, categorizing them as racially balanced or unbalanced while limiting racially balanced datasets to have each race be represented within five percentage points of all other represented races. We investigate methods to address concerns about racial bias due to uneven datasets by using generative adversarial networks and latent diffusion models to balance the data, and we also assess the impact of these techniques. In an effort to mitigate accuracy discrepancies across different racial groups, we investigate a range of network enhancements in facial recognition performance across human races. These improvements encompass architectural improvements, loss functions, training methods, data modifications, and incorporating additional data. Additionally, we discuss the interrelation of racial and gender bias. Lastly, we outline avenues for future research in this domain.
A Joint Optimization Algorithm for UAV Location and Offloading Decision Based on Wireless Power Supply
Authors: Sun Shuo , Zhu Qi
Published: June 2024

In this paper, a joint optimization algorithm of offloading decision, energy harvesting time, and unmanned aerial vehicle (UAV) location is proposed for user equipment (UEs)’s task completion latency problem in a communication–sensing–computing integration scenario with wireless energy supply. Under the constraints of causality of energy harvesting consumption by the UEs and conditional mutual information, the total latency minimization problem of the UEs is established. Firstly, the optimization variables of the problem are transformed from three variables of offloading decision, energy harvesting time, and UAV location to two variables of offloading decision and UAV location by means of the derived closed expression, and then the transformed optimization problem is decomposed into the offloading decision optimization sub-problem and the UAV location optimization sub-problem to be solved alternately and iteratively. The genetic algorithm is employed to tackle the optimization sub-problem of offloading decisions, and the successive convex approximation algorithm is applied to the drone positioning optimization sub-problem. Simulation results show that the proposed algorithm in this paper reduces the average task completion latency by 35 percent and 15 percent, respectively, compared to the two baseline algorithms for different numbers of UEs.
Hybrid Advanced Control Strategy for Post-Combustion Carbon Capture Plant by Integrating PI and Model-Based Approaches
Authors: Ilea Flavia-Maria , Cormos Ana-Maria , Cristea Vasile Mircea , Cormos Calin-Cristian
Published: June 2024

Even though the energy penalties and solvent regeneration costs associated with amine-based absorption/stripping systems are important challenges, this technology remains highly recommended for post-combustion decarbonization systems given its proven capture efficacy and technical maturity. This study introduces a novel centralized and decentralized hybrid control strategy for the post-combustion carbon capture plant, aimed at mitigating main disturbances and sustaining high system performance. The strategy is rooted in a comprehensive mathematical model encompassing absorption and desorption columns, heat exchangers and a buffer tank, ensuring smooth operation and energy efficiency. The buffer tank is equipped with three control loops to finely regulate absorber inlet solvent solution parameters, preventing disturbance recirculation from the desorber. Additionally, a model-based controller, utilizing the model predictive control (MPC) algorithm, maintains a carbon capture yield of 90% and stabilizes the reboiler liquid temperature at 394.5 K by manipulating the influent flue gas to the lean solvent flowrates ratio and the heat duty of the reboiler. The hybrid MPC approach reveals efficiency in simultaneously managing targeted variables and handling complex input–output interactions. It consistently maintains the controlled variables at desired setpoints despite CO2 flue gas flow disturbances, achieving reduced settling time and low overshoot results. The hybrid control strategy, benefitting from the constraint handling ability of MPC, succeeds in keeping the carbon capture yield above the preset minimum value of 86% at all times, while the energy performance index remains below the favorable value of 3.1 MJ/kgCO2.
Mathematical Modeling, Parameters Effect, and Sensitivity Analysis of a Hybrid PVT System
Authors: Ahmed Md Tofael , Rashel Masud Rana , Abdullah-Al-Wadud Mohammad , Hoque Tania Tanzin , Janeiro Fernando M. , Tlemcani Mouhaydine
Published: June 2024

Hybrid PVT solar systems offer an innovative approach that allows solar energy to be used to simultaneously generate thermal and electrical energy. It is still a challenge to develop an energy-efficient hybrid PVT system. The aim of this work is to develop a mathematical model, investigate the system’s performance based on parameters, include sensitivity analysis in the upper layer mainly photovoltaic part, and provide an efficient and innovative system. Performance analysis of the hybrid system is obtained by establishing a mathematical model and efficiency analysis. The electrical model and thermal model of the hybrid system is also obtained by appropriate and complete mathematical modeling. It establishes a good connection of the system in the context of electrical analysis and power generation. The parameters variation impact and sensitivity analysis of the most important parameters, namely, irradiance, ambient temperature, panel temperature, wind speed, and humidity in the PV panel section, are also obtained using a MATLAB model. The results show the effective increase or decrease in the electrical power and sensitiveness in the output of the system due to this modification. Related MPP values as a result of these parameters variation and their impact on the overall output of the hybrid PVT system are also analyzed.
An Improved Onboard Adaptive Aero-Engine Model Based on an Enhanced Neural Network and Linear Parameter Variance for Parameter Prediction
Authors: Pang Shuwei , Lu Haoyuan , Li Qiuhong , Gu Ziyu
Published: June 2024

Achieving measurable and unmeasurable parameter prediction is the key process in model-based control, for which an accurate onboard model is the most important part. However, neither nonlinear models like component level models or LPV models, nor linear models like state–space models can fully meet the requirements. Hence, an original ENN-LPV linearization strategy is proposed to achieve the online modelling of the state–space model. A special network structure that has the same format as the state–space model’s calculation was applied to establish the state–space model. Importantly, the network’s modelling ability was improved through applying multiple activation functions in the single hidden layer and an experience pool that records data of past sampling instants, which strengthens the ability to capture the engine’s strongly nonlinear dynamics. Furthermore, an adaptive model, consisting of a component-level model with adaptive factors, a linear Kalman filter, a predictive model, an experience pool, and two ENN-LPV networks, was developed using the proposed linearization strategy as the core process to continuously update the Kalman filter and the predictive model. Simulations showed that the state space model built using the ENN-LPV linearization strategy had a better model identification ability in comparison with the model built using the OSELM-LPV linearization strategy, and the maximum output error between the ENN-LPV model and the simulated engine was 0.1774%. In addition, based on the ENN-LPV linearization strategy, the adaptive model was able to make accurate predictions of unmeasurable performance parameters such as thrust and high-pressure turbine inlet temperature, with a maximum prediction error within 0.5%. Thus, the effectiveness and the advantages of the proposed method are demonstrated.
Development of Low-Cost c-Si-Based CPV Cells for a Solar Co-Generation Absorber in a Parabolic Trough Collector
Authors: Aydin Elsen , Buchroithner Armin , Felsberger Richard , Preßmair Rupert , Azgın Ahmet , Turan Rasit , Keçeci Ahmet Emin , Bektaş Gence , Akinoglu Bulent
Published: June 2024

Concentrator photovoltaics (CPVs) have demonstrated high electrical efficiencies and technological potential, especially when deployed in CPV–thermal (CPV-T) hybrid absorbers, in which the cells’ waste heat can be used to power industrial processes. However, the high cost of tracking systems and the predominant use of expensive multi-junction PV cells have caused the market of solar co-generation technologies to stall. This paper describes the development and testing of a low-cost alternative CPV cell based on crystalline silicone (c-Si) for use in a novel injection-molded parabolic hybrid solar collector, generating both, photovoltaic electricity and thermal power. The study covers two different c-Si cell technologies, namely, passive emitter rear contact (PERC) and aluminum back surface field (Al-BSF). Simulation design and manufacturing are described with special attention to fingerprinting in order to achieve high current carrying capacities for concentrated sunlight. It was determined that Al-BSF cells offer higher efficiencies than PERC for the considered use case. Solar simulator tests showed that the highly doped 4 cm2 cells (50 ohm/sq) reach efficiencies of 16.9% under 1 sun and 13.1% under 60 suns at 25 °C with a temperature coefficient of −0.069%(Abs)/K. Finally, options to further improve the cells are discussed and an outlook is given for deployment in a field-testing prototype.
A Graph-Based Genetic Algorithm for Distributed Photovoltaic Cluster Partitioning
Authors: Liu Zhu , Hu Wenshan , Guo Guowei , Wang Jinfeng , Xuan Lingfeng , He Feiwu , Zhou Dongguo
Published: June 2024

To easily control distributed photovoltaic power stations and provide fast responses for their regulation, this paper proposes an optimal cluster partitioning method based on a graph-based genetic algorithm (GA). In this approach, a novel structure utilizing a graph model is designed for chromosomes, and enhancements are made to the selection, crossover, and mutation models of the evolutionary to generate a search population for dividing distributed photovoltaic (PV) power grids into clusters. Moreover, the modularity and active power balance degree of the classic Girvan–Newman algorithm are employed as optimal objectives to establish a basis and evaluation system for cluster partitioning. Additionally, a Simulink simulation platform is established for the IEEE 33-bus time-varying scenario to validate its performance. A comparative analysis with some classic PV cluster partitioning algorithms demonstrates that the proposed method can achieve a more accurate and stable division of distributed PV units.
Effect Evaluation of Staged Fracturing and Productivity Prediction of Horizontal Wells in Tight Reservoirs
Authors: Zhang Yuan , Chen Jianyang , Wu Zhongbao , Xiao Yuxiang , Xu Ziyi , Cheng Hanlie , Zhang Bin
Published: June 2024

In this paper, the effect evaluation and production prediction of staged fracturing for horizontal wells in tight reservoirs are studied. Firstly, the basic characteristics and value of horizontal wells in tight reservoirs are introduced, their geological characteristics, flow mechanism and permeability model are analyzed and the application of grey theory in effect analysis is discussed. Considering the problems of staged fracturing effect evaluation and the production prediction of horizontal wells in tight reservoirs, a BP neural network model based on deep learning is proposed. Due to the interference of multiple physical parameters and the complex functional relationship in the development of tight reservoir fracturing, the traditional prediction method has low accuracy and it is difficult to establish an accurate mapping relationship. In this paper, a BP neural network is used to simulate multivariable nonlinear mapping by modifying the model, and its advantages in solving the coupling relationship of complex functions are brought into play. A neural network model with fracturing parameters as input and oil and gas production as output is designed. Through the training and testing of data sets, the accuracy and applicability of the proposed model for effect evaluation and yield prediction are verified. The research results show that the model can fit the complex mapping relationship between fracturing information and production and provide an effective evaluation and prediction tool for the development of the staged fracturing of horizontal wells in tight reservoirs.
The Role of State Aid in the Achievement of the Energy Efficiency Objective in the Food Industry—The Example of Poland
Authors: Zuba-Ciszewska Maria , Suchoń Aneta
Published: June 2024

The aims of the article are to assess the legal conditions for improving energy efficiency in the energy-intensive food industry in Poland, including the rules for financing enterprises from public funds, and to assess the extent of state aid for these enterprises in their pursuit of energy saving goals. A critical analysis of the literature and of legal regulations on energy efficiency in EU and Polish law has been performed. The analysis of state aid is based on SUDOP data, and it takes into account the time span, the food industry structure, the enterprise size, the type and purpose of aid granted, and the degree of aid concentration. The conducted research showed that the largest share of state aid is received by energy-intensive industries, i.e., meat, fruit and vegetables, and dairy products (65.5%), and by large- and medium-sized enterprises (82.4%). This aid was allocated through various programmes and in various forms, the most important of which were subsidies. The aid focused on three objectives, i.e., promotion of energy from renewable sources, high-efficiency cogeneration, and measures supporting energy efficiency. The study shows the development of legislation on energy efficiency and possibilities for financing investments, both at the EU and national levels. Tightening climate policy will enhance the importance of energy efficiency in the food industry, which should be reflected in an increase in the relatively low current level of this aid (amounting to 0.04% of total state aid and 0.17% of aid for environmental protection and energy purposes).