bluuebunny/crossref_metadata_2025 huggingface dataset:
Incipient fault detection and condition assessment in DFIGs based on external leakage flux sensing and modified multiscale poincare plots analysis
Authors: Zhao Shouwang , Chen Yu , Liang Feng , Zhang Sichao , Shahbaz Nadeem , Wang Shuang , Zhao Yong , Deng Wei , Cheng Yonghong
Published: October 2023

Although doubly fed induction generators (DFIG) are widely used, difficulties in early fault detection and severity assessment for inter-turn short-circuit (ITSC) faults are highly prominent. In this manuscript, a novel incipient fault detection and state assessment method based on external leakage flux sensing and modified multiscale poincare plots (MMSPP) is proposed. An external leakage flux sensor is placed on the axial-end position of the generator to monitor the presence and evolution of ITSC faults. Multiscale poincare mapping is a novel nonlinear tool that is further developed and modified using the normal cumulative distribution function and multiscale computing methods to capture the behavior evolution and changes in the generator’s external leakage flux signals. The healthy indicator is based on the analysis of elliptical orbit features extracted from MMSPP, established by support vector data description with parameter optimization. The effectiveness of the proposed method was implemented and verified under an experimental environment on a 100 kW DFIG platform to detect incipient inter-turn short circuits (mainly considering the two-turn ITSC) and evaluate the performance degradation (three- to eight-turn ITSC) with 0%, 50%, and 100% different load conditions. The experimental results showed the viability of the approach and fault indicator for incipient fault detection and condition assessment of the wind generator’s low inter-turn insulation faults and for relative quantification of ITSC fault severity.
Designing architectured ceramics for transient thermal applications using finite element and deep learning
Authors: Kiyani Elham , Yazdani Sarvestani Hamidreza , Ravanbakhsh Hossein , Behbahani Razyeh , Ashrafi Behnam , Rahmat Meysam , Karttunen Mikko
Published: October 2023

Topologically interlocking architectures have demonstrated the potential to create durable ceramics with desirable thermo-mechanical properties. However, designing such materials poses challenges due to the intricate design space, rendering traditional modeling approaches ineffective and impractical. This paper presents a novel approach to designing high-performance architectured ceramics by integrating machine learning (ML) techniques and finite element analysis (FEA) data. The design space of interlocked architectured ceramics encompasses tiles with varying angles and sizes. The study considers three configurations

3
×
3

,

5
×
5

, and

7
×
7

arrays of tiles with five sets of interlocking angles

(

5
∘

,

10
∘

,

15
∘

,

20
∘

,

a
n
d

25
∘

)

. By training ML models, specifically convolutional neural networks (CNNs) and multilayer perceptrons (MLPs) using FEA simulation data, we establish correlations between architectural parameters and thermo-mechanical characteristics. A grid comprising all possible designs was generated to predict high-performance architectured ceramics. This grid was then fed into the networks that were trained using results from the FEA simulation. The predicted results for all possible interpolated designs are utilized to determine the optimal structure among the configurations. The goal is to identify the optimal interlocked ceramics that minimize the out-of-plane deformation for thermal shielding and maximize heat absorption for heat sink applications. To validate the performance of the outcomes, FEA simulations were conducted on the best predictions obtained from both the MLP and CNN algorithms. Despite the limited amount of available simulation data, our networks demonstrate effectiveness in predicting the transient thermo-mechanical responses of potential panel designs. Notably, the optimal design predicted by CNN led to

≈
30
%

improvement in edge temperature.
Discretely-supported transfer nanoimprint anti-reflection nanostructures on complex uneven surface of Fresnel lenses
Authors: Wang Chunhui , Sun Jiaxing , Fan Yu , Shao Jinyou
Published: October 2023

Nanopatterning complex uneven surface of numerous functional devices to improve their performance is significantly appealing; however, it is extremely challenging. This study proposes a discretely-supported transfer nanoimprint technique to fabricate nanostructures on complex device surfaces containing multi-spatial frequencies. First, a discretely-supported nanoimprint template was designed based on the built energy criterion. A contact fidelity of over 99% was achieved between the designed template and the targeted complex uneven substrate surface. Next, the prefilled nanostructures on the template were transferred to the target surface after contact. By precisely controlling the amount of micro-droplet jetting on the template on-demand, the accumulation of the polymer in the micro-valley sites on the complex substrate was avoided, thus maintaining the morphology and generating function of the devices. Finally, high-quality Fresnel lenses with broadband wide-directional antireflection and excellent imaging performance were developed by imprinting subwavelength-tapered nanostructures on the relief surface.
Epsilon-near-zero material-based bi-layer metamaterials for selective mid-infrared radiation
Authors: Chen Ju , Liu Xianghui , Wang Pan , Xiao Chengyu , Chen Shaowen , Zhou Han
Published: October 2023

Selective mid-infrared (MIR) radiation is highly desirable in many applications. However, there are still great challenges to simultaneously achieve MIR camouflage and radiative cooling utilizing simple structure. This work theoretically and experimentally proposes a bi-layer metamaterial composed of aluminum doped zinc oxide (AZO) nanoparticles embedded in Al2O3 matrix on the aluminum film. The bi-layer metamaterial exhibits high performance in MIR camouflage with radiative cooling, a low emissivity (

ε

3
−
5
μ
m

= 0.11,

ε

8
−
14
μ
m

= 0.20) in atmospheric windows and a high emissivity (

ε

5
−
8
μ
m

= 0.81) in non-atmospheric windows. The interaction of the epsilon-near-zero (ENZ) mode and localized surface plasmon resonance (LSPR) mode is responsible for the perfect emission over the wavelength range of 5–8

μ

m. Additionally, the proposed selective MIR emitter supports large-angle incidence and has great polarization insensitivity. This demonstrates that epsilon-near-zero material-based bi-layer metamaterial is highly promising for the development of selective mid-infrared radiation.
Anti-motion imaging photoplethysmography via self-adaptive multi-ROI tracking and selection
Authors: Duan Yaran , He Chao , Zhou Mei
Published: October 2023

Objective. The imaging photoplethysmography (IPPG) technique allows people to measure heart rate (HR) from face videos. However, motion artifacts caused by rigid head movements and nonrigid facial muscular movements are one of the key challenges. Approach. This paper proposes a self-adaptive region of interest (ROI) pre-tracking and signal selection method to resist motion artifacts. Based on robust facial landmark detection, we split the whole facial skin (including the forehead, cheeks, and chin) symmetrically into small circular regions. And two symmetric sub-regions constitute a complete ROI. These ROIs are tracked and the motion state is simultaneously assessed to automatically determine the visibility of these ROIs. The obscured or invisible sub-regions will be discarded while the corresponding symmetric sub-regions will be retained as available ROIs to ensure the continuity of the IPPG signal. In addition, based on the frequency spectrum features of IPPG signals extracted from different ROIs, a self-adaptive selection module is constructed to select the optimum IPPG signal for HR calculation. All these operations are updated per frame dynamically for the real-time monitor. Results. Experimental results on the four public databases show that the IPPG signal derived by our proposed method exhibits higher quality for more accurate HR estimation. Compared with the previous method, metrics of the evaluated HR value on our approach demonstrates superior or comparable performance on PURE, VIPL-HR, UBFC-RPPG and MAHNOB-HCI datasets. For instance, the RMSEs on PURE, VIPL-HR, and UBFC-RPPG datasets decrease from 4.29, 7.62, and 3.80 to 4.15, 3.87, and 3.35, respectively. Significance. Our proposed method can help enhance the robustness of IPPG in real applications, especially given motion disturbances.
The spatial density distribution of H2O2 in the effluent of the COST-Jet and the kINPen-sci operated with a humidified helium feed gas
Authors: Harris B , Krös L , C Nave A S , Wagenaars E , van Helden J H
Published: October 2023

Cold atmospheric plasma jets operated with a helium feed gas containing small admixtures of water vapour are excellent sources of H2O2 for direct biomedical applications. However, H2O2 is typically distributed non-uniformly throughout the effluent region, meaning the dosage received by a patient or substrate is dependent on their positioning relative to the plasma source. This study presents the spatial distribution of absolute H2O2 number densities in the effluent of two popular plasma jets, the COST-Jet and the kINPen-sci plasma jet, when operated with a humidified helium feed gas. The measurements were performed using continuous wave cavity ring-down spectroscopy with a tunable, mid-infrared laser. The H2O2 number density measured close to the jet nozzle is 2.3

×

1014 cm−3 for the kINPen-sci plasma jet and 1.4

×

1014 cm−3 for the COST-Jet. The average number density of H2O2 in the effluent of the kINPen-sci plasma jet is a factor of two higher than in the effluent of the COST-Jet. The distribution of H2O2 in the COST-Jet effluent is initially highly uniform and suggests negligible mixing of H2O2 with the ambient air up to 15 mm from the jet nozzle, although it is rapidly diluted at further distances. In the case of the kINPen-sci plasma jet, the number density of H2O2 has a more pronounced radial distribution close to the nozzle, while the mixing with the ambient air is more gradual at further distances from the nozzle. It is evident that a detailed understanding of the H2O2 production in the plasma source, as well as of the transport of H2O2 to the substrate through the effluent, is required in order to optimise the intended effects. This work serves to highlight the difference of the distinct spatial distribution of H2O2 in the effluent of both types of plasma jets when considering their direct application in biomedicine.
Variable stiffness methods for robots: a review
Authors: Li Zhang , Chu Xiaoyu , Hu Xinye , Zhang Zhiyi , Li Nanpei , Li Junfeng
Published: October 2023

Traditional robots with constant stiffness demonstrate reliable output power and positioning precision, which may conversely reduce their flexibility and adaptability or even incur greater damage for accidental collisions with the environment or humans. Here, we review state-of-the-art robots with a variable stiffness mechanism, which is a key design concept that is widely used to improve robot reliability and impart new functionalities. To determine the similarities and differences between variable stiffness methods, we discuss the existing principles for variable stiffness of both rigid and soft robots, such as coupled and uncouple structures, thermal stimuli and magneto-rheological approaches. We hope this paper can help readers better understand these methods with regard to interesting applications. In addition, we also outline challenges and perspectives, where a simpler structure, larger band and faster response of stiffness modulation are required for robots in the future.
A superradiant two-level laser with intrinsic light force generated gain
Authors: Bychek Anna , Ritsch Helmut
Published: October 2023

The implementation of a superradiant laser as an active frequency standard is predicted to provide better short-term stability and robustness to thermal and mechanical fluctuations when compared to standard passive optical clocks. However, despite significant recent progress, the experimental realization of continuous wave superradiant lasing still remains an open challenge as it requires continuous loading, cooling, and pumping of active atoms within an optical resonator. Here we propose a new scenario for creating continuous gain by using optical forces acting on the states of a two-level atom via bichromatic coherent pumping of a cold atomic gas trapped inside a single-mode cavity. Analogous to atomic maser setups, tailored state-dependent forces are used to gather and concentrate excited-state atoms in regions of strong atom-cavity coupling while ground-state atoms are repelled. To facilitate numerical simulations of a sufficiently large atomic ensemble, we rely on a second-order cumulant expansion and describe the atomic motion in a semi-classical point-particle approximation subject to position-dependent light shifts which induce optical gradient forces along the cavity axis. We study minimal conditions on pump laser intensities and detunings required for collective superradiant emission. Balancing Doppler cooling and gain-induced heating we identify a parameter regime of a continuous narrow-band laser operation close to the bare atomic frequency.
Phase-locking an interferometer with single-photon detections
Authors: Hacker Bastian , Günthner Kevin , Rößler Conrad , Marquardt Christoph
Published: October 2023

We report on a novel phase-locking technique for fiber-based Mach–Zehnder interferometers based on discrete single-photon detections, and demonstrate this in a setup. Our interferometer decodes relative-phase-encoded optical pulse pairs for quantum key distribution applications and requires no locking laser in addition to the weak received signal. Our new simple locking scheme is shown to produce an Ornstein–Uhlenbeck dynamic and achieve optimal phase noise for a given count rate. In case of wavelength drifts that arise during the reception of Doppler-shifted satellite signals, the arm-length difference gets continuously readjusted to keep the interferometer phase stable.
Constraints on the ghost-free parity-violating gravity from laser-ranged satellites
Authors: Qiao Jin , Li Zhao , Ji Ran , Zhu Tao , Li Guoliang , Zhao Wen , Chen Jiming
Published: October 2023

This paper explores the evolutionary behavior of the Earth-satellite binary system within the framework of the ghost-free parity-violating gravity and the corresponding discussion on the parity-violating effect from the laser-ranged satellites. For this purpose, we start our study with the Parameterized Post-Newtonian (PPN) metric of this gravity theory to study the orbital evolution of the satellites in which the spatial-time sector of the spacetime is modified due to the parity violation. With this modified PPN metric, we calculate the effects of the parity-violating sector of metrics on the time evolution of the orbital elements for an Earth-satellite binary system. We find that among the five orbital elements, the parity violation has no effect on the semi-latus rectum, while the eccentricity and ascending node are affected only in a periodic manner. These three orbital elements are the same as the results of general relativity and are also consistent with the observations of the present experiment.
In particular, parity violation produces non-zero corrections to the eccentricity and pericenter, which will accumulate with the evolution of time, indicating that the parity violation of gravity produces observable secular effects. The observational constraint on the parity-violating effect is derived by confronting the theoretical prediction with the observation by the LAGEOS II pericenter advance, giving a constraint on the parity-violating parameter space from the satellite experiments.
A Galaxy Morphology Classification Model Based on Momentum Contrastive Learning
Authors: Shen Guoqiang , Zou Zhiqiang , Luo A-Li , Hong Shuxin , Kong Xiao
Published: October 2023

The taxonomy of galaxy morphology plays an important role in astrophysics and provides great help for the study of galaxy evolution. To integrate the advantages of unsupervised learning without labels and supervised learning with high classification accuracy, this paper proposes a galaxy morphology classification model based on a momentum contrastive learning algorithm named Momentum Contrastive Learning Galaxy (MCL-Galaxy), which mainly includes two parts (i) pre-training of the model, where the ResNet_50 backbone network acts as an encoder to learn the galaxy morphology image features, which are stored in the queue and their consistency is ensured by using the momentum contrastive learning algorithm; and (ii) transfer learning, where Mahalanobis distance can assist in improving classification accuracy in downstream tasks where both encoder and queue are transferred. To evaluate the performance of MCL-Galaxy, we use the data set of the Galaxy Zoo challenge project on Kaggle for comparative testing. The experimental results show that the classification accuracy of MCL-Galaxy can reach 90.12%, which is 8.12% higher than the unsupervised state-of-the-art results. Although it is 3.1% lower than the advanced supervised method, it has the advantage of no label and can achieve a higher accuracy rate at the first epoch of classification iteration. This suggests that the gap between unsupervised and supervised representation learning in the field of Galaxy Morphologies classification tasks is well bridged.
A Multimodal Transfer Learning Method for Classifying Images of Celestial Point Sources
Authors: Wang Bingjun , Hong Shuxin , Yuan Zhiyang , Luo A-Li , Kong Xiao , Zou Zhiqiang
Published: October 2023

A large fraction of celestial objects exhibit point shapes in CCD images, such as stars and QSOs, which contain less information due to their few pixels. Point source classification based solely on image data may lead to low accuracy. To address this challenge, this paper proposes a Multi-modal Transfer Learning-based classification method for celestial objects with point shape images. Considering that spectral data possess rich features and that there is a correlation between spectral data and image data, the proposed approach fully utilizes the knowledge gained from celestial spectral data and transfers it to the original image-based classification, enhancing the accuracy of classifying stars and QSOs. Initially, a one-dimensional residual network is employed to extract a 128-dimensional spectral feature vector from the original 3700-dimensional spectral data. This spectral feature vector captures important features of the celestial object. The Generative Adversarial Network is then utilized to generate a simulated spectral vector of 128 dimensions, which corresponds to the celestial object image. By generating simulated spectral vectors, data from two modals (spectral and image) for the same celestial object are available, enriching the input features of the model. In the upcoming multimodal classification model, we only require the images of celestial objects along with their corresponding simulated spectral data, and we no longer need real spectral data. With the assistance of spectral data, the proposed method alleviates the above disadvantages of the original image-based classification method. Remarkably, our method has improved the F1-score from 0.93 to 0.9777, while reducing the error rate in classification by 40%. These enhancements significantly increase the classification accuracy of stars and QSOs, providing strong support for the classification of celestial point sources.
Improvement of Digest2 NEO Classification Code—utilizing the Astrometry Data Exchange Standard
Authors: Vereš Peter , Cloete Richard , Weryk Robert , Loeb Abraham , Payne Matthew J.
Published: October 2023

We describe enhancements to the digest2 software, a short-arc orbit classifier for heliocentric orbits. Digest2 is primarily used by the Near-Earth Object (NEO) community to flag newly discovered objects for a immediate follow-up and has been a part of NEO discovery process for more than 15 yr. We have updated the solar system population model used to weight the digest2 score according to the 2023 catalog of known solar system orbits and extended the list of mean uncertainties for 140 observatory codes. Moreover, we have added Astrometry Data Exchange Standard (ADES) input format support to digest2, which provides additional information for the astrometry, such as positional uncertainties for each detection. The digest2 code was also extended to read the roving observer astrometric format as well as the ability to compute a new parameter from the provided astrometric uncertainties (

RMS
′

) that can serve as an indicator of in-tracklet curvature when compared with tracklet’s great-circle fit rms. Comparison with the previous version of digest2 confirmed the improvement in accuracy of NEO identification and found that using ADES XML input significantly reduces the computation time of the digest2.
Recent progress on valley polarization and valley-polarized topological states in two-dimensional materials
Authors: Wang 王 Fei 斐 , Zhang 张 Yaling 亚玲 , Yang 杨 Wenjia 文佳 , Zhang 张 Huisheng 会生 , Xu 许 Xiaohong 小红
Published: October 2023

Valleytronics, using valley degree of freedom to encode, process, and store information, may find practical applications in low-power-consumption devices. Recent theoretical and experimental studies have demonstrated that two-dimensional (2D) honeycomb lattice systems with inversion symmetry breaking, such as transition-metal dichalcogenides (TMDs), are ideal candidates for realizing valley polarization. In addition to the optical field, lifting the valley degeneracy of TMDs by introducing magnetism is an efficient way to manipulate the valley degree of freedom. In this paper, we first review the recent progress on valley polarization in various TMD-based systems, including magnetically doped TMDs, intrinsic TMDs with both inversion and time-reversal symmetry broken, and magnetic TMD heterostructures. When topologically nontrivial bands are empowered into valley-polarized systems, valley-polarized topological states, namely valley-polarized quantum anomalous Hall effect can be realized. Therefore, we have also reviewed the theoretical proposals for realizing valley-polarized topological states in 2D honeycomb lattices. Our paper can help readers quickly grasp the latest research developments in this field.
Valleytronic topological filters in silicene-like inner-edge systems
Authors: Xie 谢 Hang 航 , Lü 吕 Xiao-Long 小龙 , Yang 杨 Jia-En 加恩
Published: October 2023

Inner edge state with spin and valley degrees of freedom is a promising candidate for designing a dissipationless device due to the topological protection. The central challenge for the application of the inner edge state is to generate and modulate the polarized currents. In this work, we discover a new mechanism to generate fully valley- and spin–valley-polarized current caused by the Bloch wavevector mismatch (BWM). Based on this mechanism, we design some serial-typed inner-edge filters. By using once of the BWM, the coincident states could be divided into transmitted and reflected modes, which can serve as a valley or spin–valley filter. In particular, while with twice of the BWM, the incident current is absolutely reflected to support an off state with a specified valley and spin, which is different from the gap effect. These findings give rise to a new platform for designing valleytronics and spin-valleytronics.
Progressive unsupervised control of myoelectric upper limbs
Authors: Gigli Andrea , Gijsberts Arjan , Nowak Markus , Vujaklija Ivan , Castellini Claudio
Published: October 2023

Objective. Unsupervised myocontrol methods aim to create control models for myoelectric prostheses while avoiding the complications of acquiring reliable, regular, and sufficient labeled training data. A limitation of current unsupervised methods is that they fix the number of controlled prosthetic functions a priori, thus requiring an initial assessment of the user’s motor skills and neglecting the development of novel motor skills over time. Approach. We developed a progressive unsupervised myocontrol (PUM) paradigm in which the user and the control model coadaptively identify distinct muscle synergies, which are then used to control arbitrarily associated myocontrol functions, each corresponding to a hand or wrist movement. The interaction starts with learning a single function and the user may request additional functions after mastering the available ones, which aligns the evolution of their motor skills with an increment in system complexity. We conducted a multi-session user study to evaluate PUM and compare it against a state-of-the-art non-progressive unsupervised alternative. Two participants with congenital upper-limb differences tested PUM, while ten non-disabled control participants tested either PUM or the non-progressive baseline. All participants engaged in myoelectric control of a virtual hand and wrist. Main results. PUM enabled autonomous learning of three myocontrol functions for participants with limb differences, and of all four available functions for non-disabled subjects, using both existing or newly identified muscle synergies. Participants with limb differences achieved similar success rates to non-disabled ones on myocontrol tests, but faced greater difficulties in internalizing new motor skills and exhibited slightly inferior movement quality. The performance was comparable with either PUM or the non-progressive baseline for the group of non-disabled participants. Significance. The PUM paradigm enables users to autonomously learn to operate the myocontrol system, adapts to the users’ varied preexisting motor skills, and supports the further development of those skills throughout practice.
Improving Hydraulic Fracturing Productivity in Khalda Oil Fields (Western Desert -Egypt)
Authors: Ahmed Ahmed Abuzeid , Bayoumi Abdel Wahab Abdel Hameed
Published: October 2023

The hydraulic fracturing technique is used to create a highly conductive path between the reservoir and wellbore at an economic rate. There are two types of hydraulic fracturing based on the pumping schedule: the first is the conventional hydraulic fracturing which uses continuous pumping schedule and forms a proppant pack inside the fracture. The second is the channel hydraulic fracturing which uses intermittent (pulsing) pumping schedule and forms proppant pillars inside the fracture. The aim of this work is to study the factors affecting the fracture conductivity of the channel fracturing technique. Technical and economical comparison has been conducted between the above-mentioned two types of fracturing using real production data. The Fracturing Computer-Aided Design and Evaluation (FracCADE) simulator was utilized for this purpose. The results indicate that the conductivity of the channel fracturing technique is greater than that of the conventional one. The pulse time and perforated cluster length were found to have a significant effect on the fracture conductivity because of their influence on the pillar spacing. The results indicate also that: the cost of the channel fracturing is greater than that of the conventional one by about 26.28 %. However, the NPV of the produced oil by the channel fracturing is more than the same of the conventional one. In addition, the payout time of the channel fracturing is shorter which means a faster return of investments.
Exploration of the comparison method between nuclear magnetic logging porosity and core detection porosity
Authors: Jiang Gui-pu , Fu Yan , Shen Zhong-shan , Yu Wen , Cao Teng-fei , Du Ying , Liu Min , Lei Yu-ming , Dai Ming-duo , Li Yi-xiao
Published: October 2023

Porosity is the basis of reservoir parameter interpretation, permeability and saturation parameters are closely related to porosity, and the interpretation model of porosity has been established with the correlation between core porosity and electrical properties, and core porosity is the effective porosity measured by applying liquid saturation method. With the application of nuclear magnetic logging technology, the interpretation of porosity is more refined and can be subdivided into total porosity, effective porosity, capillary-bound water porosity, and clay-bound water porosity. In order to apply the nuclear magnetic logging technology more accurately, it is necessary to find a method to compare the two porosity detection methods. In this paper, we discuss the meaning of core porosity through the operation procedure of core detection porosity, combined with core piezometric curve and core density calculation method, get the conclusion that core detection porosity approximates total porosity, explore the comparison method between total porosity and core porosity of nuclear magnetic logging, and lay the geological foundation for the next step of applying nuclear magnetic logging data to improve porosity interpretation.
Seismic Identification and Hydrocarbon Accumulation Characteristics of Submarine Fan in offshore Suriname
Authors: Bian Hai-guang , Wen Zhi-xin , Wang Zhao-ming , He Zheng-jun , Song Cheng-peng , Liu Zuo-dong , Wang Xue-ling , Li Heng-xuan , Ji Tian-yu
Published: October 2023

In recent years, oil and gas fields have been continuously discovered in the Suriname-Guyana Basin of South Atlantic, the reservoir of which is submarine turbidite sandstone and become one of the hot exploration objectives in the world. Based on the interpretation and analysis of 2D seismic and well data, this paper presents the integrated geological and geophysical evaluation of the Suriname-Guyana basin within Suriname and describes the identification characteristics and hydrocarbon accumulation process of submarine fan in offshore Suriname. The tectonic evolution of this region can be divided into four stages, breakup of Pangea, intracontinental rift, regional uplift and drifting over the South Atlantic. The Upper Cretaceous marks the transition of a transgressive to a regressive system with increasing sediment input from the south west, creating a broad delta plain environment across the shallow offshore area. It has been confirmed that multi-stage submarine fans have developed from Upper Cretaceous to Neogene in offshore Suriname, with overlapping characteristics of multiple erosive surfaces. It is suggested that erosive surface forming local unconformity is the important identification mark of submarine fan. Among them, the Paleogene and Upper Cretaceous submarine fans are the most widely distributed and have the most obvious characteristics on seismic profiles. The bottom of the Paleogene and Upper Cretaceous fans are identified by the erosive surfaces. The fan root has obvious characteristics of cutting valley, forming inter-bedded with the deep-sea facies toward the outer fan, along with litho-logic granularity thinning and scope expansion. The distal parts of the submarine fan are surrounded by abyssal shale, which can form a good source, reservoir and cap configuration. Therefore, turbidite fan sandstone with good source rock and cap configuration is the favorable reservoir.
Research on the Fault Diagnosis Method of Reciprocating Compressors Based on the Probability Diagram Model
Authors: Liu Wencai , Wang Xiaofei , Zhang Jinxing , Zheng Huiyong
Published: October 2023

A reciprocating compressor is one of the key pieces of equipment in the petrochemical production industry. Its structure is complex and there are many sources of excitation causing vibration, making the analysis of the causes of failure challenging. Depending upon fault types, the failures in reciprocating compressors can be classified as leakage, wear, fracture, loosening, impact, blockage, etc.; depending upon where the faults occur, the failures can be classified by components affected such as a valve type, a transmission component type, a sealing component type, etc. This paper proposes a parameter self-learning method for diagnosing mechanical faults. With a probability diagram model for the “fault-sign” relationship on the equipment established according to Bayesian networks, the paper proposes a parameter self-learning method in which, based on the failure rate curve, the prior probability is determined subject to the double-parameter Weibull distribution while the conditional probability can be adjusted automatically according to the diagnosis results. After the probability diagram diagnosis model is built, it collects real-time operating data of the equipment, extracts eigenvalues, sets alarm thresholds, and enters into the diagnosis model the comparison results between the eigenvalues and alarm thresholds as the node states in the sign layer. The changes of the node states in the sign layer will change the posterior probabilities of the corresponding nodes in the fault layer so as to deliver the set of diagnosis results with the highest probability of fault occurrence, thus achieving the purpose of diagnosing the equipment fault.
Flow characteristics around the crack in pipeline
Authors: Ali Jafar A , Ahmed Payman S
Published: October 2023

Pipelines transport fluids especially petroleum and its products, the transportation process may face some problems due to the defects that can occur in the pipes. Cracks are the main defects that attack the pipes and reduce their performance. It is known that the flow around cracks in pipelines are complicated and affected by various factors, it worth to be considered before decision making on the pipeline integrity. In this study flow characteristics around the crack inside the pipeline has been investigated. The part of the pipe within the crack is the crack zone, where the flow behaviour is different with the rest of the pipe. The work carried out at the laboratory using pipes with different crack length and crude oil with known properties to observe the flow at the crack zone. Then the work theoretically analysed with computational fluid dynamics to model the flow. It is found that the fluid at the crack zone is going to be more viscous lead to accumulation and changes in the characteristics of the flow. The results revealed that the flow characteristics in cracked pipeline with no leakage depend on several factors; the size of the crack, temperature, pressure, velocity and fluid viscosity.
Analysis of Well Performance Based on Bottom Hole Pressure Calculations for Gas Lift Application
Authors: Mohamed Nader , Abdallah Elhassan Mostafa. , Almahdawi Faleh H. , Mukhtar Yasir M. F.
Published: October 2023

This paper focuses on optimizing gas lift techniques in four wells located in the North Sea to overcome the common issue of low reservoir pressure. Gas lift is a common artificial lift technique used in wells with low reservoir pressure where the natural pressure of the reservoir is insufficient to bring the oil to the surface. The success of gas lift optimization depends on identifying the deepest injection point, gas injection rate, and pressure of the gas injected. The paper proposes the deepest injection points for wells A-03, A-09A, A-10T2, and A-12BT2 as 3809.38 ft, 6649.7 ft, 3559.88 ft, and 3979.04 ft, respectively. The injection rates analyzed in this paper range from 1-10 mmscf/day, and injection pressures of 500 psia, 1000 psia, and 1500 psia were used. The response of each well to gas lift was analyzed, and increasing injection rate and pressure were found to increase oil production rate. The optimal gas injection rate and pressure for wells A-03, A-09A, and A-12BT2 were found to be 10 mmscf/day and 1500 psia, while for well A-12BT2, the best oil recovery was obtained at an injection rate of 3 mmcsf/day and injection pressure of 1500 psia. Tubing size within the range of 1-5.5 inch was examined, and it was found that increasing tubing size enhances oil flow rate. The optimal tubing size for the wells was found to be 5.5 inch, taking into consideration factors such as flow rate, pressure, temperature requirements, and fluid type.
Research and Application of HSE Control System for High Consequence Area Water Injection Pipeline
Authors: Qi Shen , Wang Xue-mei , Zhou Peng , Ji Jia-xiu , Zhao Li-juan , Deng Wen-bin
Published: October 2023

In view of the fact that the safety management technology prevention and control capabilities are weak in the safety management technology such as long operating life, high pipeline operating pressure, large control area, difficulty in detecting abnormal phenomena, slow valve opening and closing speed, and difficulty in quickly handling emergencies in oilfields, the HSE control system of water injection pipelines in high consequence areas is developed and designed with the help of technical means such as Internet of Things and edge gateway computing, which realizes real-time monitoring of water injection pipeline pressure in high consequence areas, remote control of shut-off valves, timely elimination of hidden dangers, and timely control of dangerous situations. Purpose of expeditious disposal. This research project was tested in the field of a branch of a water injection line in a typical high-consequence area. The verification results show that the system has the functions of real-time monitoring of water injection pressure and remote control of shut-off valve, which is of great significance for improving the HSE technical defense system of oilfield and improving the ability of oilfield to deal with emergencies.
Dynamics Analysis of Droplets Collision with the Wall Driven by Buoyancy
Authors: Rong Feng , He Li-min , Lü Yu-ling , Wang Ce , Han Yi-shuo
Published: October 2023

Dynamics analysis of the oil droplet in water impacting on a rigid wall in the range of Re=9.3 ∼ 231.39, We=0.003 ∼ 0.637 was carried out by combining microscopic experiment with theoretical study. In the oil droplet’s force equation, we consider the added mass force and the water film induced force, in addition to the conventional forces, i.e. buoyancy and resistance to flow. Stokes-Reynolds drainage equation (i.e. SR model) and Young-Laplace equation (i.e. YL model) are combined with the force equation to numerically solve the motion law of oil droplets near the wall for different control parameters. The study indicates that coupled model would expect oil droplet velocities, motion trajectories and capture the kinetic behaviors of the water-film drainage evolution. The interfacial deformation of oil droplets causes changes in the pressure and the pressure distribution pattern has an important relationship with the shape of the oil droplet interface. These two forces play a dominant role in droplet motion during the collision and the maximum value of these two forces increases with increasing droplet size and Re number. Future research should shift towards complex oil-water systems and consider the effects of chemicals on oil droplets so that the application of the model will be more generalisable. At the same time, computer technology should be used to transfer the two-dimensional view to a three-dimensional view to analyse the deformation of the oil-water interface and to better understand the drainage process of the water film.
Uniform Acid Cleaning Technology and Its Application in Horizontal Wells with Open Hole Screen Tube
Authors: Jia Peifeng , Cui Chuanzhi , Sui Yingfei , Ren Jiamin , Lv Chao
Published: October 2023

After the completion of the open hole sieve tube in a horizontal well, it is necessary to replace the slurry and put it into production. Generally, circulating acid outside the tube cannot fully remove mud pollution. The acidification process needs to fully consider the heel effect of horizontal wells. Based on the horizontal pipe flow model and the characteristics of foam diversion, a mathematical model of acid washing suitable for open hole screen horizontal wells is established. Analysis suggests that lower flow rates and higher fluid viscosity during the acid washing process are more conducive to the uniform entry of the plugging solution into the formation. We have designed a uniform liquid mixing equipment with a flow blocking mechanism, and improved the acid washing construction process to achieve negative pressure reverse discharge of acid solution. This process can achieve uniform entry of the unblocking fluid into the formation after passing through the screen gap, and remove the blockage of the mud layer inside and outside the near screen tube. The horizontal wells using this process have a 30% increase in production capacity compared to oil wells in the same block, and the high yield validity period has been extended by 680 days.
An S-band MMIC LNA in GaAs 0.15-μm pHEMT
Authors: Liang Ruirui , He Wenlong
Published: October 2023

The study adopts a monolithic microwave integrated circuit (MMIC) low-noise amplifier (LNA) applied in S-band was designed using ADS simulation software, GaAs 0.15-um pseudomorphic high electron mobility transistor (pHEMT) process. The LNA small signal gain is greater than 30.8 dB, gain flatness is ±0.45 dB, noise coefficient is less than 1.5 dB, input and output return loss is greater than 10 dB, and the chip area is 1.2*2.4 mm2. The low noise amplifier is composed of a two-stage cascade structure. Gain flatness, gain control, and bandwidth broadening are improved by RLC negative feedback network. The minimum noise coefficient circle and maximum gain circle are narrowed by adding negative feedback to achieve better noise coefficient and gain.
Security label and attribute-based access control in service-oriented environments
Authors: Cao Jingyi , Yin Liang , Li Menglin , Zhu Yayun , Zhang Hongjie , Zhang Xiaojuan , Lin Ziqing , Hu Baiji , Yao Shuang , Peng Jianing
Published: October 2023

Compared with traditional systems, service-oriented environments are more dynamic and distributed. Although traditional access control is able to fulfill the security of requirements of closed systems on the whole, it can no longer meet the requirements of service-oriented environments. To deal with the issues that access control in the service-oriented environment needs to cross the boundary of the security domain, the high distribution, and heterogeneity of environmental characteristics, and how to establish efficient and guaranteed access to resources, access control based on security label and attribute is proposed for fine-grained resource information and rich policy security requirements. By using a CP-ABE mechanism, distributed fine-grained access control can be realized in the company of solving the issue of policy privacy leakage; By using the security label technology, the multi-level security mandatory access control is realized, and the security flow of information is achieved, thus protecting the service and its methods from unauthorized users. Finally, the proposed scheme has been verified to have reliable security through security analysis. The experimental outcomes indicate this proposed scheme is available and effective in terms of performance.
A Novel Power System Side Channel Attack Method Based on Machine Learning CNN-Transformer
Authors: Zhang Xiaojuan , Zhu Yayun , Hu Baiji , Cao Jingyi , Lin Ziqing
Published: October 2023

Continuous advancements in cryptography and information technology have rendered current cryptographic algorithms highly robust against traditional cryptanalysis methods. However, in modern power systems, the equipment’s inherent process characteristics result in the leakage of side channel information during the operation of cryptographic algorithms. This information includes power consumption, electromagnetic signals, and timing data. Adversaries can exploit these side channels to compromise encryption keys. To address this issue, a groundbreaking power system side-channel attack method is introduced in this paper, leveraging the CNN-Transformer architecture in machine learning. The proposed approach utilizes power consumption analysis techniques to identify relevant points of interest in the side channel power consumption data. By employing a machine learning model for training, encryption can be breached. Empirical results demonstrate the superior attack efficiency of the model compared to LSTM and CNN models in side channel attacks.
Temporal Role Access Control Model for New Power Systems Based on Trust Degree
Authors: Wu Kehe , Han Yang , Tian Zheng , Wu Weidong , Sun Yizhen
Published: October 2023

With the continuous development of information construction in the new power system and the power information network system, users have their own role identities in the corresponding business systems, and access permissions change over time. Traditional access control permanently assigns user roles, which has made the issue of power information security increasingly prominent. This article introduces time constraints in the role-based access control of the new power system. Building on the research of GTRBAC, a trust-based time-constrained role-based access control model for the new power system is proposed. The model’s semantics, execution model, and formal verification are defined.
Recording channel design for time-based measurements in 28 nm CMOS
Authors: Kadlubowski L.A. , Kmon P.
Published: October 2023

In this paper we present a recording stage dedicated to
time-based measurements required in imaging detectors. The prototype
ASIC is manufactured in the 28 nm CMOS process and consists of a
8 × 4-pixel matrix of 50 μm pitch. Each pixel includes
a recording stage that processes input signals for the digital
circuitry, responsible for performing time-based measurements such
as Time-over-Threshold and Time-of-Arrival. The digital part of the
pixel is made up of two ring-based oscillators, configuration
registers, and counters. The recording channel occupies only
12 × 50 μm while consuming 4.5 μA current. The
in-pixel coarse and fine correction methods implemented allowed an
improvement of gain and offset uniformity 3.3 and 10 times,
respectively.
Fast forward modeling of neutral beam injection and halo formation including full Balmer-α emission prediction at W7-X
Authors: Bannmann S. , Ford O. , Hoefel U. , Poloskei P. , Pavone A. , Kwak S. , Svensson J. , Lazerson S. , McNeely P. , Rust N. , Hartmann D. , Pasch E. , Fuchert G. , Wolf R.C. , the W7-X-Team the
Published: October 2023

A full collisional-radiative (CR) neutral beam injection model based on Gaussian pencil (Gausscil) beams and a diffusive CR neutral halo model are presented. The halo is a neutral cloud around the neutral beam forming due to multiple charge exchange (CX) reactions. Both models do not rely on Monte-Carlo techniques and are thereby orders of magnitude faster than commonly used models. To model the neutral halo a system of coupled diffusion equations is solved numerically, enforcing mixed boundary conditions. From the equilibrium hydrogen neutral densities in the second excited energy state (n = 3), the Balmer-α emission intensity is calculated and the full spectrum is predicted, including effects as Doppler shifts and broadening due to the complex neutral beam geometry and the motional Stark effect (MSE) from the magnetic field. All forward models are implemented in the Minerva [1] Bayesian analysis framework to enable detailed multivariant inference from Balmer-α spectroscopy data. The modeled neutral beam and halo densities are successfully verified against calculations with a validated Monte-Carlo code for the W7-X beam and plasma geometry, especially proving the validity of the halo diffusion ansatz. A comparison of the predicted emission spectra with the experimental data proves the accuracy of the implemented model. All important parameters defining the neutral beams are inferred and compared to available reference values.