bluuebunny/crossref_metadata_2025_split huggingface dataset:
Advancements in bearing remaining useful life prediction methods: a comprehensive review
Authors: Song Liuyang , Lin Tianjiao , Jin Ye , Zhao Shengkai , Li Ye , Wang Huaqing 
Published: May 2024

Abstract
This paper presents a comprehensive review of the state-of-the-art techniques for predicting the remaining useful life (RUL) of rolling bearings. Four key aspects of bearing RUL prediction are considered: data acquiring, construction of health indicators, development of RUL prediction algorithms, and evaluation of prediction results. Additionally, publicly available datasets that can be used to validate bearing prediction algorithms are described. The existing RUL prediction algorithms are categorized into three types and have been comprehensively reviewed: physical-based, statistical-based, and data-driven. In particular, the progress made in data-driven prediction methods is summarized, and typical methods such as rerrent neural network, convolutional network, graph convolutional network, Transformer, and transfer learning-based methods are introduced in detail. Finally, the challenges faced by data-driven methods in RUL prediction for bearings are discussed.
Nonlinear optical properties of KnCl (n = 2–7) superalkali clusters
Authors: Şentürk Şükrü , Fardad Fraidoon , Ekincioğlu Yavuz 
Published: May 2024

Abstract
The lowest energy structures along with the low lying isomer, stabilities, electronic properties, optical properties and nonlinear optical responses of KnCl (n = 2–7) clusters were studied within the density functional theory. The second order energy difference, dissociation energy and GH-L (HOMO–LUMO gap) point out that KnCl (n = 3, 5, 7) clusters are more stable. The calculated adiabatic ionization energies (AIE) for the KnCl (n = 2–6) clusters are in agreement with the measured ionization energies. The optical properties, namely optical electronegativity and refractive index, depends on the GH-L energy values. The K atom capped planar rhombus geometry of the K4Cl causes the noticeable vibrational frequency shift compared to the rest of IR spectra of the clusters. The first static hyperpolarizability (β
o) values are in the range of 2.33 × 103
–2.87 × 104 au and the second static hyperpolarizability varies between 5.74 × 106 au and 38.9 × 106 au for the cluster. The nonlinear optical response is due to the superalkali nature of KnCl (n = 2–7) clusters. From computed β
vec values, the hyperpolarizability has projection on the dipole moment vector for the superalkalis except the K2Cl and K5Cl. The absorption spectra point out that KnCl (n = 6–7) clusters can be suitable as a NLO material since they have transparency in the deep UV region (λ< 300 nm).
Hybrid minigrid system comprising energy storage systems with optimal frequency control empowering the new Egypt large optical telescope site
Authors: Abdelkareem Mohamed , Abdelghany A M , Azzam Yosry Ahmed , Ebrahim Mohamed Ahmed , Abdelghany M A 
Published: May 2024

Abstract
Proposed hybrid minigrid two area system simulation model encompassing Photo Voltaic (PV) system, Wind Turbines (WT), diesel generators and Energy Storage Systems with intelligent based optimal Frequency Controllers (FCs) empowering the new Egypt large optical telescope (ELOT) site is presented in this research. Technical study and specifications for a PV solar system of 1000 Kw is introduced. Intelligent fine optimized Proportional Integral Derivative (PID) and Fuzzy self-tuned PID (FSTPID) controllers are designed through applying Harris Hawk optimizer (HHO). The proposed HHO employed method performance is validated under number of eventualities which include vacillations of load, sun radiation and wind speed. The objective function and control parameters are the integral time summation of absolute deviations and the parameters of controllers, consecutively. The system dynamic response and simulation results show that the proposed HHO based FSTPID type FCs are effective in reducing frequency and tie line power signals’ deviations in a diminutive time for such minigrid hybrid system. For supplemental validations, simulation results obtained are compared with genetic algorithm to get the proposed controllers’ gains.
One-dimensional quantum scattering from multiple Dirac δ − potentials: a Python-based solution
Authors: Keshavarz Erfan , Mazharimousavi S Habib 
Published: May 2024

Abstract
In this research, we present a Python-based solution designed to simulate a one-dimensional quantum system that incorporates multiple Dirac δ − potentials. The primary aim of this research is to investigate the scattering problem within such a system. By developing this program, we can generate wave functions throughout the system and compute transmission and reflection amplitudes analytically and numerically for an infinite range of combinations involving potential strengths, potential separations, and the number of potential centers in the form of the Dirac δ − functions. Furthermore, by modifying the code, we investigate the so-called ‘transmission resonances’ which yields the energy of the quantum particles undergoing a perfect transmission. Subsequently, our research is extended by considering impurities in the system.
A novel semi-supervised deep learning method for enhancing discriminability and diversity in EEG-based emotion recognition task
Authors: Waleed Al-Asadi Ahmed , Salehpour Pedram , Aghdasi Hadi S 
Published: May 2024

Abstract
Numerous deep learning models have been introduced for EEG-based Emotion recognition tasks. Nevertheless, the majority of these models are fully supervised, demanding substantial amounts of labeled EEG signals. The labeling process of EEG signals is both time-intensive and costly, involving numerous trials and meticulous analysis by experts. Recently, some advanced semi-supervised algorithms that can achieve a competitive performance with fully-supervised methods by using only a small set of labeled data have been presented. However, these algorithms are primarily developed for the image data type, and naïve adaptation of them for EEG applications results in unsatisfactory performance. To address this issue, we present a robust semi-supervised EEG-based method that exploits the best techniques from advanced semi-supervised algorithms in the computer vision domain enriched with novel regularization terms for unlabeled signals. The proposed regularization terms improve both the discriminability and diversity of the model’s predictions and effectively leverage prior knowledge about the class distributions, thereby achieving a superior performance compared to the distribution alignment techniques in state-of-the-art methods. We evaluate our method on the DEAP dataset for cross-subject valence/arousal emotion recognition tasks, and on the SEED in a cross-session setting. The results indicate that the proposed method consistently surpasses the peer methods at different numbers of labeled data by a large margin.
Friction stir additive manufactured AA 6061/TiC/GS composite: assessment of microstructural and mechanical properties
Authors: Maurya Manish , Kumar Sudhir , Maurya Ambrish 
Published: May 2024

Abstract
Friction stir additive manufacturing (FSAM) technique was used to fabricate the composite. Present investigation deals with the additive manufacturing of three AA 6061 sheets filled with TiC/GS particles in a groove with the variation reinforcement wt-%. Micro-structural investigation of the fabricated sample was conducted through optical microscopy, SEM and EDS. Optical and SEM results depict the uniform dispersal of the TiC and GS particles in the processed zone. Due to hard TiC and GS particles embedded in AA 6061, an improvement in hardness by 37.2% was observed for AA 6061/4 wt-%TiC/6 wt-%GS composite. Tensile and compressive strength was enhanced by 25.8% and 11% for the developed material. Corrosion test and thermal expansion behavior was investigated for the fabricated composite. 0.2 gm was the weight loss observed for the sample kept in NaCl solution for 72 h. Negligible amount of thermal expansion was noticed for the prepared material. TiC and GS particles, observed in the fractographic image shows the brittle fracture. EDS analysis confirmed the existence of elements like Al, Mg, Mn etc in the surface of the specimens. The present experimental results were also compared from the previous published work by the various academicians.
Bubble misalignment mechanism for axions
Authors: Lee Junseok , Murai Kai , Takahashi Fuminobu , Yin Wen 
Published: May 2024

Abstract
We study the dynamics of axions at first-order phase transitions in non-Abelian gauge theories.
When the duration of the phase transition is short compared to the timescale of the axion oscillations, the axion dynamics is similar to the trapped misalignment mechanism. On the other hand, if this is not the case, the axions are initially expelled from the inside of the bubbles, generating axion waves on the outside. Analogous to the Fermi acceleration, these axions gain energy by repeatedly scattering off the bubble walls. Once they acquire enough energy, they can enter the bubbles.
If the axion oscillations are relevant only inside the bubbles during the phase transition, the axion abundance is significantly enhanced compared to models where the axion mass is either constant or varies continuously as a function of temperature. The increase in axion abundance depends on the axion mass, the duration of the phase transition, and the bubble wall velocity.
This mechanism results in a spatially inhomogeneous distribution of axions, which could lead to the formation of axion miniclusters.
It has potential implications for
the formation of oscillons/I-balls, axion warm dark matter, cosmic birefringence,
and the production of dark photons.
Collapsing universe before time
Authors: Shiu Gary , Tonioni Flavio , Tran Hung V. 
Published: May 2024

Abstract
In this note, we prove analytic bounds on the equation of state of a cosmological fluid composed of an arbitrary number of canonical scalars evolving in a negative multi-exponential potential. Because of the negative energy, the universe is contracting and eventually undergoes a big crunch. A contracting universe is a fundamental feature of models of ekpyrosis and cyclic universes, which are a proposed alternative to cosmic inflation to solve the flatness and horizon problems. Our analytic bounds set quantitative constraints on general effective theories of ekpyrosis. When applied to specific top-down constructions, our bounds can be used to determine whether ekpyrosis could in principle be realized. We point out some possible sources of tension in realizing the ekpyrotic universe in controlled constructions of string theory.
Remarks on overestimating the effects of inhomogeneities on the Hubble constant
Authors: Miura Taishi , Tanaka Takahiro 
Published: May 2024

Abstract
The Hubble constant is one of the most important parameters in cosmology. Discrepancies
in values of the Hubble constant estimated from various measurements, the so-called Hubble
tension, are a serious problem. In this paper, we study the effects of small-scale
inhomogeneities of structure formation on the measurement of the Hubble constant using the
luminosity distance-redshift relation. By adopting the adhesion model in Newtonian cosmology as
the model of structure formation, we investigate whether or not the effects of inhomogeneities can
be sufficiently large to affect the current observations of the Hubble constant. We show that
inappropriate treatment of the effects of inhomogeneities can cause a large deviation of the
measured value of the Hubble constant from the background value, whose magnitude is comparable
with the Hubble tension. Our main message is the importance of adopting an appropriate model of
structure formation to investigate the effects of inhomogeneities. We also add discussion on the
spatial averaging approach used to estimate the measured Hubble constant in the
inhomogeneous universe.
The possible

K

K

¯

*

and

D

D

¯

*

bound and resonance states by solving the Schrodinger equation
Authors: Sun Bao-Xi , Cao Qin-Qin , Sun Ying-Tai 
Published: May 2024

Abstract
The Schrodinger equation with a Yukawa type of potential is solved analytically. When different boundary conditions are taken into account, a series of solutions are indicated as a Bessel function, the first kind of Hankel function and the second kind of Hankel function, respectively. Subsequently, the scattering processes of

K

K

¯

*

and

D

D

¯

*

are investigated. In the

K

K

¯

*

sector, the f
1(1285) particle is treated as a

K

K

¯

*

bound state, therefore, the coupling constant in the

K

K

¯

*

Yukawa potential can be fixed according to the binding energy of the f
1(1285) particle. Consequently, a

K

K

¯

*

resonance state is generated by solving the Schrodinger equation with the outgoing wave condition, which lies at 1417 − i18 MeV on the complex energy plane. It is reasonable to assume that the

K

K

¯

*

resonance state at 1417 − i18 MeV might correspond to the f
1(1420) particle in the review of the Particle Data Group. In the

D

D

¯

*

sector, since the X(3872) particle is almost located at the

D

D

¯

*

threshold, its binding energy is approximately equal to zero. Therefore, the coupling constant in the

D

D

¯

*

Yukawa potential is determined, which is related to the first zero point of the zero-order Bessel function. Similarly to the

K

K

¯

*

case, four resonance states are produced as solutions of the Schrodinger equation with the outgoing wave condition. It is assumed that the resonance states at 3885 − i1 MeV, 4029 − i108 MeV, 4328 − i191 MeV and 4772 − i267 MeV might be associated with the Zc(3900), the X(3940), the χ

c1(4274) and χ

c1(4685) particles, respectively. It is noted that all solutions are isospin degenerate.
Piezoelectric fibers based on silk fibroin with excellent output performance
Authors: Zhen 甄 Wenqiang 文强 , Chen 陈 Jie 杰 , Fan 范 Suna 苏娜 , Zhang 张 Yaopeng 耀鹏 
Published: May 2024

Abstract
The self-powered tissue engineering scaffold with good biocompatibility is of great significance for stimulating nerve cell growth. In this study, silk fibroin (SF)-based fibers with regulatable structure and piezoelectric performance are fabricated by dry-spinning and post-treatment. The concentration of SF and calcium ion in spinning dope and the post-treatment affect the conformation transition and crystallinity of SF. As a result, the SF fibers exhibit high piezoelectric coefficient d
33 (3.24 pm/V) and output voltage (∼ 27 V). Furthermore, these piezoelectric fibers promote the growth of PC-12 cells, demonstrating the promising potential for nerve repair and other energy harvester.
Security analysis of satellite-to-ground reference-frame-independent quantum key distribution with beam wandering
Authors: Zhou 周 Chun 淳 , Zhao 赵 Yan-Mei 燕美 , Yang 杨 Xiao-Liang 晓亮 , Lu 陆 Yi-Fei 宜飞 , Zhou 周 Yu 雨 , Jiang 姜 Xiao-Lei 晓磊 , Wang 汪 Hai-Tao 海涛 , Wang 汪 Yang 洋 , Li 李 Jia-Ji 家骥 , Jiang 江 Mu-Sheng 木生 , Wang 汪 Xiang 翔 , Zhang 张 Hai-Long 海龙 , Li 李 Hong-Wei 宏伟 , Bao 鲍 Wan-Su 皖苏 
Published: May 2024

Abstract
The reference-frame-independent (RFI) quantum key distribution (QKD) is suitable for satellite-based links by removing the active alignment on the reference frames. However, how the beam wandering influences the performance of RFI-QKD remains a pending issue in satellite-to-ground links. In this paper, based on the mathematical model for characterizing beam wandering, we present the security analysis for satellite-to-ground RFI-QKD and analytically derive formulas for calculating the secret key rate with beam wandering. Our simulation results show that the performance of RFI-QKD is better than the Bennett–Brassard 1984 (BB84) QKD with beam wandering in asymptotic case. Furthermore, the degree of influences of beam wandering is specifically presented for satellite-to-ground RFI-QKD when statistical fluctuations are taken into account. Our work can provide theoretical support for the realization of RFI-QKD using satellite-to-ground links and have implications for the construction of large-scale satellite-based quantum networks.
Observed decade-long improvement of combustion efficiency in the Yangtze River Delta region in China
Authors: Zhao Jiarui , Chen Huilin , Qi Ximeng , Chi Xuguang , Jia Mengwei , Jiang Fei , Zhong Sheng , Zheng Bo , Ding Aijun 
Published: May 2024

Abstract
The ΔCO/ΔCO2 ratio is a good indicator of the combustion efficiency of carbon-containing fuels, and can be useful to assess the combustion efficiency on a regional scale. In this study, we analyzed in-situ observations of CO2 and CO concentrations from 2011 to 2021 at the Station for Observing Regional Processes of the Earth System (SORPES), in the Yangtze River Delta (YRD) region of eastern China, and calculated the ΔCO/ΔCO2 ratio to investigate the combustion efficiency in the YRD region. Furthermore, we used a Lagrangian particle dispersion model WRF-FLEXPART to evaluate the contribution of each emission sources to the observed ΔCO/ΔCO2 ratio. We found that the observed ΔCO/ΔCO2 ratio showed a persistent decreasing trend of 1.0 ppb/ppm per year and decreased ∼47.9% during this period, illustrating an evident improvement in the combustion efficiency in the YRD region. The improvement of the combustion efficiency is a result of China’s Air Pollution Prevention and Control Action Plan announced in 2013. However, the decrease of ΔCO/ΔCO2 ratio slowed down from 1.3 ppb ppm−1 per year during 2011–2016 to 0.6 ppb ppm−1 per year during 2017–2021. The simulation results reveal that the slowdown of the decrease in the ΔCO/ΔCO2 ratios can be explained by the slowing improvement of combustion efficiency in steel source in the industry sector. Our results verify the effectiveness of emission reduction efforts in the YRD region and highlight the necessity of long-term observations of CO2 and CO.
Analysis of rainwater utilization for landscaping and sanitation needs at Kalvari Church, Jakarta
Authors: Pranoto W A , Jin O F , Dharmawan I , Gunawan F 
Published: May 2024

Abstract
This study examines the potential of rainwater harvesting for addressing flooding and water scarcity issues at Calvary Church Lubang Buaya, Jakarta. Utilizing primary and secondary data, we calculated the rainwater harvesting potential by considering the building’s roof area, runoff coefficient, and average mainstay rainfall. During the rainy season, the average monthly rainfall was 244.35 mm/month, while it dropped to 0 mm/month during the dry season. To ensure water availability in the dry season, we recommend constructing a concrete tub with a storage capacity of 255 m3. Through rainwater harvesting, the church can annually save approximately Rp. 899,201. This sustainable approach offers a practical solution for the church’s landscaping and sanitation needs, contributing to water management efforts in Jakarta. Rainwater harvesting stands as an eco-friendly and cost-effective strategy to mitigate water-related challenges faced by the city.
Hydrological model of Ciawi dry dam using GPM satellite data
Authors: Mulyono R R B H , Pramana Y H , Fisanto H , Hastorini S , Yudhistira D D 
Published: May 2024

Abstract
Ciawi Dam is the first dry dam in Indonesia. The benefits of the dam are to reduce flooding in the capital city of Jakarta, especially at a 50-year return period. The operation of the dam using 1 conduit unit aims to cut the flood peak. The flood discharge analysis that has been used so far is very limited due to the lack of existing rainfall data. So that calculations are carried out using corrected satellite data. In addition, flood discharge is also calibrated to the discharge at the Katulampa Weir. Analysis of the design rainfall shows the value of design rainfall with 50-year return (R50) is 210.59 mm and the 50-year flood discharge (Q50) is 317.13 m3/dt. The flood reduction value at the 50-year return period is 27%. If an alternative water gate is added, the flood reduction value can increase up to 72% with an opening of 30%.
Analysis of Drought Index and Soil Infiltration to Control Fire Risk in Tropical Peatland Forest
Authors: Novitasari N , Nurfansyah N , Effendi R , Rusdiansyah R , Nailia N , Ramadhani M A , Maulana M , Fitriati U 
Published: May 2024

Abstract
Peatlands in Indonesia cover an area of more than 7% of the land area, around 14.95 million hectares spread over the islands of Sumatra, Kalimantan, Papua, and a small part of Sulawesi. Peatlands are made use of by establishing a drainage system and clearing land. Due to the peatland’s inability to absorb water, land fires and irreversible drying are all consequences. This also takes place in a protected forest in Liang Anggang Protected Forest. The purpose of this study is to reduce the risk of fire in Liang Anggang Protected Forest by establishing a correlation between the drought index on peatlands and infiltration data. Based on an understanding of the hydrological processes that occur in peatlands, which are characterized by reduced rainfall, high drought index values, and the soil’s ability to absorb water, especially in the dry season. From June to October, especially in September, the soil is very dry. It is vulnerable to fire. Extreme caution is required in the land management process with fire from the citizens around the area.
Water Loss in the Benanain River from Temef Dam to Haekto and Benanain Weirs in East Nusa Tenggara
Authors: Edhisono S , Sachro S S 
Published: May 2024

Abstract
Water loss always occurs in the process of delivering water from the water source to the user structures. The Benanain River, which is a natural channel, is a means of carrying water from Temef Dam to Haekto Weir to irrigate Haekto Irrigation Area and Benanain Weir which is used to irrigate Malaka Irrigation Area. The length of the river from Temef Dam to Haekto Weir is 23,689 m and from Haekto Weir to Benanain Weir is 21,673 m with a total length of 45,362 m. Along the way, water loss occurs due to the influence of evaporation, percolation, river cross-sectional area and river length. This research looked for water loss that occurred in the river and obtained an average result for the Temef Dam - Haekto Weir section of 0.243 m3/second and for the Haekto Weir - Benanain Weir section of 0.183 m3/second.
Application of QUAL2Kw for Water Quality Modeling in the Cibarani Irrigation Channel, Bandung City, Indonesia
Authors: Fitriana F , Yudianto D , Seo Y C 
Published: May 2024

Abstract
The Cikapundung River, a vital water source for Bandung City, has faced substantial water pollution in recent decades, primarily due to rapid population growth. A significant contributor to this pollution has been the Cibarani Irrigation Channel, situated within the heart of Bandung City. This channel has transformed into a conduit for domestic sewage, receiving excess rainwater and household wastewater from the surrounding residential areas. Remarkably, despite the pronounced contamination, the local community continues to utilize this water source for activities such as fish farming and washing. This study aims to evaluate the quality of the Cibarani irrigation channel and determine the pollutant load the channel receives from each domestic waste inlet. The results indicate that the Cibarani irrigation channel’s water quality, based on DO, NH3-N, and TP concentrations, does not meet the Class II raw water quality standard. The concentrations of DO and TP from domestic wastewater are 2 mg/L and 3 mg/L, respectively, while the NH3-N concentration, ranging from 10-40 mg/L, surpasses the permissible limit of domestic wastewater quality standards. It was also discovered that the downstream BOD concentration significantly exceeds the allowable limit despite the wastewater concentration not exceeding the standard limit.