bluuebunny/crossref_metadata_2025 huggingface dataset:
Considerations on prediction horizon and dissipative losses for wave energy converters
Authors: Shahroozi Zahra , Göteman Malin , Engström Jens , Todalshaug Jørgen Hals
Published: September 2021

The non‐causal optimal control law for wave energy converters leads to a requirement of predicting waves and wave forces over a future horizon. Using examples of generic body shapes and oscillation modes, the authors show through computations of the velocity reference trajectory how the length of prediction horizon required to reach the maximum power output depends on the level of dissipative losses in the conversion chain . The sensitivity to noise is discussed, and so is the use of filtering to improve performance when the available prediction horizon is short or predictions are inaccurate . Considerations are also made for amplitude constraints and other effects encountered in a real system. With realistic assumptions for the level of dissipative losses, results indicate that the prediction horizon needed to approach the maximum achievable power output for real systems ranges from only a few seconds up to about half a wave period, which is shorter than that has generally been assumed earlier.
Heliospheric effects caused by Sun-originating versus LISM-advected fluctuations
Authors: Strumik M. , Ratkiewicz R.
Published: September 2021

Context. We investigate the response of the heliosphere to fluctuations in the local interstellar medium (LISM) as compared to the influence of solar-cycle fluctuations.

Aims. We discuss the differences between effects coming from the two types of drivers of time-dependent effects in the heliosphere in the context of the shape of the heliosphere, the thickness of the inner heliosheath, and the position of the ribbon of enhanced energetic neutral particle emission, as observed by the IBEX mission.

Methods. Our study is based on a comparison of fully time-dependent simulations obtained with a three-dimensional (3D) model of the heliosphere.

Results. We show that density fluctuations, taking the form of entropy waves and originating from the LISM, may reduce the thickness of the inner heliosheath to a similar extent as the solar-cycle effects. However, the relative motions of the termination shock and the heliopause in the two types of simulations are different. The amplitude of variation of the heliopause position is greater for the LISM fluctuation. The IBEX ribbon position is shown to be not significantly affected by the two types of drivers, although the effect of LISM fluctuation is stronger than that of the solar cycle. In this context, slight systematic changes of the position of the IBEX ribbon in its different sectors (i.e., changes in the heliospheric nose followed by variations in the heliospheric flanks) may serve as an indicator of the passage of a density fluctuation in the LISM, as suggested by our study. We also discuss the difficulties in fitting the LISM parameters in the presence of time-dependent effects.
Numerical study of hybrid quantum dot light-emitting diode with different concentration of quantum dots in the emissive layer
Authors: Sheykholeslami-Nasab Pezhman , Davoudi-Darareh Mahdi , Yousefi Mohammad Hassan
Published: September 2021

In this study, a model for numerical simulation of carrier transport mechanism in the hybrid quantum dot light-emitting diodes (QD-LEDs) is presented. The carrier mobility in the polymer layer doped with quantum dots (QDs) was calculated by a proposed hopping mobility, which is a concentration-dependent mobility model based on the Gaussian distribution of density-of-states and the effective transport energy models. A QD-LED structure based on PVK:CdSe-QDs blend as the emissive layer with different QD concentrations were fabricated and their current density versus voltage (J–V) characteristic was measured. The numerical results were compared with experimental data, which indicates the ability of the proposed mobility model to describe the general trend of the electrical characteristic of the devices. Then, the exciton density profiles of the devices were extracted based on the continuity equation for singlet and triplet excitons, and the corresponding luminance characteristic of the devices was calculated. The resulted electrical and optical characteristics show that there is an optimal concentration for the QDs in the emissive layer of the QD-LEDs.
The Effect of Goal-Directed Fluid Therapy versus Standard Fluid Therapy on the Cuff Leak Gradient in Patients Undergoing Complex Spine Surgery in Prone Position
Authors: Prasad Chandrakant , Radhakrishna Nayani , Pandia Mihir Prakash , Khandelwal Ankur , Singh Gyaninder Pal , Bithal Parmod Kumar
Published: September 2021

Objective Cuff leak test is an effective and established maneuver to predict airway edema. Standard fluid therapy (SFT) based on conventional monitoring is often associated with postoperative airway edema after complex spine surgeries. We conducted this prospective randomized controlled study to compare the effect of SFT versus goal-directed fluid therapy (GDFT) on the cuff leak gradient (CLG) in patients undergoing complex spine surgery in prone position. Our secondary objectives were to compare the effect of SFT and GDFT on sore throat, hoarseness, and length of intensive care unit (ICU) and hospital stay.

Materials and Methods Thirty consecutive American Society of Anesthesiologists physical status I and II patients (18–60 years), of either sex, scheduled for spine surgery in prone position with expected duration of surgery more than 5 hours were included. The patients were randomized into two groups of 15 each. Group S patients (n = 15) served as control group and received SFT intraoperatively, while patients in group G (n = 15) received GDFT. Standard anesthetic protocol was followed in both the groups. The CLG was defined as the difference between the cuff leak volume (CLV) after intubation (CLVAI) and before extubation (CLVBE).

Statistical Analysis and Results CLG was significantly less in group G (group S, 137.12 mL; group G, 65.52 mL; p-value <0.001). Intravenous fluids, blood loss, and postoperative sore throat were comparatively lesser in group G, though not statistically significant. Postoperative hoarseness was significantly lower in group G (p-value = 0.003). Duration of ICU stay in group G (19.43 hours) was significantly lower (p-value = 0.009) than group S (24.64 hours), but length of hospital stay was comparable.

Conclusion GDFT significantly reduces airway edema and consequently reduces CLG as compared with SFT in patients undergoing complex spine surgery in prone position. Postoperatively, it also reduces sore throat, hoarseness of voice, and duration of ICU stay.
Quick Sequential Organ Failure Assessment: Modifications for Identifying Maternal Morbidity and Mortality in Obstetrical Patients
Authors: Cagino Sarah G. , Burke Alexandra A. , Letner Dorothea R. , Leizer Julie M. , Zelig Craig M.
Published: September 2021

Objective Screening tools, including the Systemic Inflammatory Response Syndrome (SIRS) criteria and Sequential Organ Failure Assessment (SOFA) criteria, have not been validated in the pregnant population. We aimed to determine if pregnancy-specific modifications to the quick SOFA (qSOFA) can improve prediction of severe maternal morbidity in pregnant women with serious infections.

Study Design We performed a retrospective cohort study of pregnant patients with severe infections admitted to a single institution from January 1, 2011, through December 31, 2017. The primary outcome was severe maternal morbidity, defined as a composite of adverse maternal outcomes: intensive care unit (ICU) admission for >48 hours, need for invasive monitoring (central line or arterial line), intubation, pharmacologic hemodynamic support (intravenous vasopressors or inotropes), and/or maternal death. A logistic regression was then applied and the resulting predictors were analyzed individually and in combination with receiver operating characteristic (ROC) curves to modify qSOFA for pregnancy, that is, qSOFA-P.

Results Analysis of 104 pregnant patients with severe infections found that the standard qSOFA did not accurately predict severe maternal morbidity (ROC area under the curve [AUC] = 0.54, p = 0.49, sensitivity = 0.38, and specificity = 0.70). Pregnancy-specific modifications or “qSOFA-P” (respiratory rate [RR] ≥ 35 breaths/minute and systolic blood pressure [SBP] ≤ 85 mm Hg) significantly improved prediction of severe maternal morbidity (AUC = 0.77, p < 0.001, sensitivity = 0.79, and specificity = 0.74).

Conclusion The standard qSOFA is a poor screening tool in the prediction of severe maternal morbidity in pregnant patients with infections. A pregnancy-specific screening system, qSOFA-P, improved prediction of severe maternal morbidity in pregnant women with severe infections. Further prospective and large multicenter studies are needed to validate this scoring system in pregnant women.

Key Points
Clinical Predictors of Vibrator-Assisted Ejaculation following Spinal Cord Injury: A Prospective Observational Study
Authors: Alisseril Sivaram , Prakash Navin B. , Chandy Bobeena Rachel , Tharion George
Published: September 2021

Introduction Infertility in men with spinal cord injury (SCI) occurs due to combination of factors like erectile dysfunction, ejaculatory failure, and semen abnormalities. Penile vibratory stimulation (PVS) is a known method of treatment for anejaculation. Predicting successful outcome of PVS depends on several clinical factors, which assess the intactness of the neural arc pertaining to the spinal ejaculation pattern generator. This study reports the clinical predictors for successful candidacy for a PVS trial in males with SCI.

Methods Twenty-three males with SCI, satisfying the inclusion criteria, were recruited in this prospective observational study. Participants underwent two trials of PVS with single high-amplitude vibrator. The clinical predictors recorded were neurological level, superficial abdominal reflex, cremasteric reflex, bulbocavernosus reflex, plantar reflex, ankle jerk, knee jerk, lower abdominal sensation, and hip flexor response. In addition, somatic responses during PVS were recorded and corelated. Participants who had successful ejaculation were “responders” and the others were termed as “nonresponders.” Binary logistic regression analysis of the clinical parameters was done to compare responders against nonresponders.

Results Of the twenty-three males (mean age 33.2 ± 6.8 years) with paraplegia, all four persons with neurological level above T9 had successful ejaculation with PVS. Among all the clinical parameters in the study, presence of somatic responses showed statistical significance in predicting successful ejaculation (p-value = 0.02).

Conclusion This study reports that in men with SCI, along with the level of injury, somatic responses and other clinical reflexes, should be considered concurrently to predict the outcome of vibrator assisted ejaculation.
Prognostic Impact of the Combination of MGMT Methylation and TERT Promoter Mutation in Glioblastoma
Authors: Tunthanathip Thara , Sangkhathat Surasak , Tanvejsilp Pimwara , Kanjanapradit Kanet
Published: September 2021

Background The concept of combinational analysis between the methylation of O6-methylguanine-DNA methyltransferase (MGMT) and telomerase reverse transcriptase promoter (pTERT) mutation in glioblastoma (GBM) has been reported. The main study objective was to determine the prognosis of patients with GBM based on MGMT/pTERT classification, while the secondary objective was to estimate the temozolomide effect on the survival time of GBM with MGMT/pTERT classification.

Methods A total of 50 GBM specimens were collected after tumor resection and were selected for investigating MGMT methylation and pTERT mutation. Clinical imaging and pathological characteristics were retrospectively analyzed. Patients with MGMT/pTERT classification were analyzed using survival analysis to develop the nomogram for forecasting and individual prognosis.

Results All patients underwent resection (total resection: 28%, partial resection: 64%, biopsy: 8%). Thirty-two percent of all cases received adjuvant temozolomide with radiotherapy. Sixty-four percent of the case was found methylated MGMT, and 56% of the present cohort found pTERT mutation. Following combinational analysis of biomarkers, results showed that the GBMs with methylated MGMT and wild-type pTERT had a superior prognosis compared with other subtypes. Using Cox regression analysis with multivariable analysis, the extent of resection, postoperative chemoradiotherapy, MGMT/pTERT classification were associated with a favorable prognosis. Hence, a web-based nomogram was developed for deploying individual prognostication.

Conclusions The interaction of MGMT methylation and pTERT mutation was confirmed for predicting prognosis. The results from the present study could help physicians create treatment strategies for GBM patients in real-world situations.
Primary Malignant Melanoma Limited to the External Auditory Canal: A Rare Presentation
Authors: Samal Dillip Kumar , Preetam C. , Sahoo Anjan Kumar
Published: September 2021

Malignant melanoma limited to the external auditory canal is very rare. These patients present relatively late as compared with melanoma involving other subsites of external ear. However, the tumor is slow-growing but shows aggressive behavior with a poor prognosis when presented late. We have a 44-year-old female who presented with a blackish lesion, which was bleeding on and off from her left ear. She was managed with wide local excision, preserving maximum part of external auditory canal cartilage. The histopathology of the lesion was suggestive of malignant melanoma. After a thorough evaluation, she was kept under close follow-up. Malignant melanoma of external auditory canal shows poor prognosis usually, mainly because of late presentation. Thus, early diagnosis is crucial, as in our case, where wide local excision was sufficing, and the patient is disease-free after 4 years of follow-up.
Parameter space for magnetization effects in high-energy-density plasmas
Authors: Sadler James D. , Li Hui , Flippo Kirk A.
Published: September 2021

Magnetic fields are well known to affect the evolution of fluids via the J × B force, where J is the current density and B is the magnetic field. This force leads to the influence of magnetic fields on hydrodynamics (magnetohydrodynamics). Magnetic fields are often neglected in modeling of high-energy-density plasmas, since J × B is very small compared with the plasma pressure gradients. However, many experiments lie in a separate part of parameter space where the plasma is indirectly affected via magnetization of the heat flux and charged particle transport. This is true even for initially unmagnetized plasmas, since misaligned density and temperature gradients can self-generate magnetic fields. By comparing terms in the induction equation, we go on to estimate the regions of parameter space where these self-generated fields are strong enough to affect the hydrodynamics.
Direct detonation initiation: A comparison between the critical curvature and critical decay rate models
Authors: Weng Z. , Mével R. , Huang Z. , Cai F. , Xu J.
Published: September 2021

The present study compares the critical initiation energy predicted by the critical curvature (CC) and critical decay rate (CDR) models. To ensure a fair and meaningful comparison between these two theoretical approaches, the Taylor–Sedov blast wave model, which enables us to relate the critical state to the energy of the point source, has been employed in both models. Simplified as well as detailed chemical mechanisms were employed for the comparison. By using the same blast wave model, the ratio of critical initiation energy calculated with the CC and CDR models was found to be one to two orders of magnitude smaller than the results in previous studies. Although the choice of the blast wave model is important, the critical energy predicted by the CC model is invariably larger than the one predicted by the CDR model. This was explained by analyzing the relationship between the shock front radius and decay time, as well as the ignition delay-time around the critical conditions of the two models. It was demonstrated that the critical conditions of the CDR model can be fulfilled more easily than those of the CC model. As a result, the main source of discrepancy between the CDR and CC models is that they adopt different initiation failure mechanisms, namely, curvature for the CC model against unsteadiness for the CDR model.
Statistical-law formulas for zero- to two-electron-transfer probabilities in proton–molecule and proton cancer therapy reactions from electron nuclear dynamics theory
Authors: Silva Eivson D. , McLaurin Patrick M. , Morales Jorge A.
Published: September 2021

We present the first quantum-mechanical derivation of statistical-law formulas to calculate zero- to two-electron transfers (ETs) in proton–molecule reactions. The original statistical derivation assumed that the n-ET probabilities of N electrons in a shell obey an N-trial binomial distribution with success probability equal to an individual one-ET probability; the latter was heuristically identified with the number of transferred electrons from the integrated charge density. The obtained formulas proved accurate to calculate ET cross sections in proton–molecule and proton cancer therapy (PCT) reactions. We adopt the electron nuclear dynamics (END) theory in our quantum-mechanical derivation due to its versatile description of ETs via a Thouless single-determinantal state. Since non-orthogonal Thouless dynamical spin-orbitals pose mathematical difficulties, we first present a derivation for a model system with N ≥ 2 electrons where only two with opposite spins are ET active; in that scheme, the Thouless dynamical spin-orbitals become orthogonal, a fact that facilitates a still intricate derivation. In the end, we obtain the number of transferred electrons from the Thouless state charge density and the ETs probabilities from the Thouless state resolution into projectile–molecule eigenstates describing ETs. We prove that those probabilities and numbers of electrons interrelate as in the statistical-law formulas via their common dependency on the Thouless variational parameters. We review past ET results of proton–molecule and PCT reactions obtained with these formulas in the END framework and present new results of H+ + N2O. We will present the derivation for systems with N > 2 electrons all active for ETs in a sequel.
Point-cloud deep learning of porous media for permeability prediction
Authors: Kashefi Ali , Mukerji Tapan
Published: September 2021

We propose a novel deep learning framework for predicting the permeability of porous media from their digital images. Unlike convolutional neural networks, instead of feeding the whole image volume as inputs to the network, we model the boundary between solid matrix and pore spaces as point clouds and feed them as inputs to a neural network based on the PointNet architecture. This approach overcomes the challenge of memory restriction of graphics processing units and its consequences on the choice of batch size and convergence. Compared to convolutional neural networks, the proposed deep learning methodology provides freedom to select larger batch sizes due to reducing significantly the size of network inputs. Specifically, we use the classification branch of PointNet and adjust it for a regression task. As a test case, two and three dimensional synthetic digital rock images are considered. We investigate the effect of different components of our neural network on its performance. We compare our deep learning strategy with a convolutional neural network from various perspectives, specifically for maximum possible batch size. We inspect the generalizability of our network by predicting the permeability of real-world rock samples as well as synthetic digital rocks that are statistically different from the samples used during training. The network predicts the permeability of digital rocks a few thousand times faster than a lattice Boltzmann solver with a high level of prediction accuracy.
Pre-impact dynamics of a droplet impinging on a deformable surface
Authors: Henman Nathaniel I. J. , Smith Frank T. , Tiwari Manish K.
Published: September 2021

The nonlinear interaction between air and a water droplet just prior to a high-speed impingement on a surface is a phenomenon that has been researched extensively and occurs in a number of industrial settings. The role that the surface deformation plays in an air cushioned impact of a liquid droplet is considered here. In a two-dimensional framework, assuming small density and viscosity ratios between the air and the liquid, a reduced system of integrodifferential equations is derived governing the liquid droplet free-surface shape, the pressure in the thin air film, and the deformation of the surface, assuming the effects of surface tension, compressibility, and gravity to be negligible. The deformation of the surface is first described in a rather general form, based on previous membrane-type models. The coupled system is then investigated in two cases: a soft viscoelastic case where the surface stiffness and (viscous) damping are considered and a more general flexible surface where all relevant parameters are retained. Numerical solutions are presented, highlighting a number of key consequences of surface deformability on the pre-impact phase of droplet impact, such as reduction in pressure buildup, increased air entrapment, and considerable delay to touchdown. Connections (including subtle dependence of the size of entrapped air on the droplet velocity, reduced pressure peaks, and droplet gliding) with recent experiments and a large deformation analysis are also presented.
USP15 antagonizes CRL4
CRBN
-mediated ubiquitylation of glutamine synthetase and neosubstrates
Authors: Nguyen Thang Van
Published: September 2021

Significance

CRBN, a substrate receptor of CUL4-RBX1-DDB1-CRBN (CRL4
CRBN
) E3 ubiquitin ligase, is a direct target for thalidomide teratogenicity and antitumor activity of immunomodulatory drugs (IMiDs) in multiple myeloma (MM) and other hematologic malignancies. IMiDs bind CRBN to recruit neosubstrates for ubiquitylation and subsequent degradation. However, it is not known whether a deubiquitinating enzyme might be involved in this process. The present study revealed that USP15 antagonizes CRL4
CRBN
-mediated ubiquitylation of natural substrate glutamine synthetase and neosubstrates, thereby preventing their degradation. Targeting USP15 sensitizes IMiD-resistant MM cells to IMiDs by promoting degradation of neosubstrates. These results suggest USP15 protein expression as a predictive biomarker of response or resistance to IMiDs and highlight the potential of USP15 as a key cancer drug target.
Why do we shake our heads?
Authors: Bross Fabian
Published: September 2021

This article discusses several arguments in favor of the hypothesis that the headshake as a gesture for negation has its origins in early childhood experiences. It elaborates on Charles Darwin’s observation that children inevitably shake their heads in order to stop food intake when sated, thereby establishing a connection between rejection and the head gesture. It is argued that later in life the semantics of the headshake extends from rejection to negation – just as it can be observed in the development of spoken language negation. While Darwin’s hypothesis can hardly be tested directly, this paper takes a novel perspective and looks at the predictions it makes taking a plethora of sources of evidence into account. The question of how head gestures are used in cultures where the headshake is not a sign for negation or where other negative head gestures are in use will also be discussed.
Context, not sequence order, affects the meaning of bonobo (Pan paniscus) gestures
Authors: Graham Kirsty E. , Furuichi Takeshi , Byrne Richard W.
Published: September 2021

In most languages, individual words can be ambiguous between several different meanings, but through syntax and context
the intended meaning of an ambiguous word usually becomes apparent. Many great ape gestures also have ambiguous meanings, which poses the
problem of how individuals can interpret the signaller’s intended meaning in specific instances. We tested the effects of sequence
compositionality and situational context (including behavioural and interpersonal contexts) in wild bonobos (Pan paniscus)
at Wamba, DRCongo. We found no effect on a gesture’s meaning from its presence and position in sequence. However, two aspects of situational
context did affect meaning: behaviour of the signaller immediately prior to gesturing, and relative age/sex of signaller and recipient. The
intended meaning of ambiguous gestures was almost completely disambiguated by means of these aspects of context. Our findings suggest that
the use of contextual information to interpret ambiguous signals predates the uniquely-human lineage and is not specific to language.
Regulatory 101: Bulk Holding Time Requirements
Authors: Zimm Karen , Phillips Renee
Published: September 2021

The FDA website provides guidance on various CGMP topics. The focus of this installment of Regulatory 101 is on the topic of bulk holding requirements. The question posed via the Q&A on CGMP’s is stated as “How long may a firm store in-process/intermediate powder blends and triturations, sustained-release pellets/beads, and tablet cores, absent separate stability studies, before using them in finished drug products?” Additional considerations are provided to further analyze this frequently asked question. Pharmaceutical products are manufactured to ensure safety, effectiveness, and quality for their intended use. As part of the product development process, stability studies are conducted to determine the appropriate shelf life for the product under specified storage conditions. These studies ensure all product specifications are met up to the assigned expiration date.
Difficulties in reconciling non-negligible differences between
the local and cosmological values
of the gravitational coupling in
extended Brans-Dicke theories
Authors: Gómez-Valent Adrià , Hassan Puttasiddappa Prajwal
Published: September 2021

Recent studies by Solà Peracaula, Gómez-Valent, de Cruz Pérez and Moreno-Pulido (2019,2020) have pointed out the intriguing possibility that Brans-Dicke cosmology with constant vacuum energy density (BD-ΛCDM) may be able to alleviate the H
0 and σ
8 tensions that are found in the framework of the concordance cosmological model (GR-ΛCDM). The fitting analyses presented in these works indicate a preference for values of the effective gravitational coupling appearing in the Friedmann equation, G, about 4–9% larger than Newton's constant (as measured on Earth), and mildly evolving with the expansion of the universe. The signal reaches the ∼ 3.5σ c.l. when the prior on H
0 from SH0ES and the angular diameter distances to strong gravitationally lensed quasars measured by H0LICOW are considered, and the ∼ 3σ c.l. when only the former is included. Thus, the improvement in the description of the cosmological datasets relies on the existence of a mechanism capable of screening the modified gravity effects at those scales where deviations from standard General Relativity (GR) are highly constrained, as in the Solar System. In this paper we explore several extensions of BD-ΛCDM that can leave the cosmological evolution basically unaltered at the background and linear perturbations level, while being able to screen the Brans-Dicke effects inside the regions of interest, leading to standard GR. We search for weak-field solutions around spherical static massive objects with no internal pressure and show that, unfortunately, these mechanisms can only explain very tiny departures of the effective cosmological gravitational coupling from the one measured locally. This might hinder the ability of BD-ΛCDM to alleviate the cosmological tensions.
Prediction of Main Engine Speed and Fuel Consumption of Inland Ships Based on Deep Learning
Authors: Lei Lin , Wen Zecheng , Peng Zhongbo
Published: September 2021

The accurate fuel consumption forecasting system is for shipping companies to carry out fuel management more effectively in order to improve economic benefits. This article aims to use deep learning algorithms to improve the accuracy of ship engine speed and fuel consumption prediction. First, the main factors affecting the engine speed and fuel consumption of inland watercrafts are analyzed, and the input parameters of the neural network model are determined. Secondly, based on the dynamic time series characteristics of inland water vessels, the LSTM (Long short-term memory) algorithm with “time parameters” was selected to establish a neural network prediction model. Finally, the difference between the LSTM deep neural network model and the traditional machine learning model is compared, and the obtained prediction data is compared with the actual data. The experimental results show the superiority of deep learning in the prediction of main engine speed and fuel consumption of inland watercraft.
A Feature Clustering-Based IP Localization Algorithm
Authors: Gan Yong , Wang Yifan , Jia Dongwei
Published: September 2021

The geographic location of network IP is an important foundation of location-based services, which plays an increasingly important role in people’s daily life and work. However, the existing IP location methods based on database query, network measurement and machine learning often have some problems, such as poor timeliness, low reliability, difficult feature modeling and so on, or need a large amount of user data as support, which is often only suitable for the more ideal network environment, so the positioning accuracy and applicability are far from the actual needs. To solve this problem, this paper proposes an IP location method based on clustering. The initial IP address of the classifier is located by training. Combined with the method of IP address database matching, the accurate location of IP address is finally realized. Experimental results show the effectiveness of the method.
Knowledge Push Method Based on Clustering Algorithm and DSM Matrix
Authors: Wang Ding , Zhan Hongfei , Yu Junhe , Wang Rui
Published: September 2021

In the process of business execution of traditional enterprises, traditional knowledge push is difficult to provide accurate knowledge support for business execution decision-making due to the complicated business problems. Therefore, this paper proposes a knowledge-push model for business execution. Firstly, the business problems in the business process are clustered through the hierarchical clustering algorithm to ensure the cohesion of the business problems after clustering. Then DSM matrix is used to represent the coupling of clustered business problems. Finally, knowledge push is carried out on the divided business problems to provide accurate knowledge support for business executives to make business problems decisions.
Research on Remote Sensing Image Target Detection Methods Based on Convolutional Neural Networks
Authors: Chen Haiwen , Wang Lu , Zhang Lei , Li Yanping , Wu Yuting , Qi Jun
Published: September 2021

Remote sensing image is extremely important for the study of natural and social phenomena and environmental analysis, remote sense image with a complex background, the goal is relatively small, arbitrary direction and disordered distribution, difficult access to information. With the continuous development of convolutional neural networks, great achievements have been made in target detection on natural images, which provides a good solution for obtaining remote sensing image information. How to improve the existing detection algorithms to make them more suitable for the characteristics of remote sensing images has become the main research direction in the current exploration of remote sensing image information. This paper reviews the existing research results of target detection on remote sensing images in detail, and finally looks forward to the future research directions of target detection methods in remote sensing images.
Towards Better Understanding of SAR Image: Feature Enhancement via Non-Local and Low-Rank Approach
Authors: Tan Xintong , Yu Qi , Wang Zelong , Zhu Jubo
Published: September 2021

Feature enhancement for synthetic aperture radar (SAR) images is of great significance for their understanding and interpretation. In this work, we aim to address the issues by introducing the low-rank constraint into non-local means framework, dubbed NL_LR. The non-local means framework takes advantages of the non-local self-similarity of SAR images, which makes this approach efficient in noise suppression and preservation of structures and resolution. When estimating the value of the target pixel, a low-rank matrix can be constructed with vectorization of similar image patches. By exploiting this low-rank prior of patch matrix and decomposition of sparse and low-rank matrices, the denoised low-rank patch matrix is more accurate which will also increase the accuracy of feature enhancement. Afterwards, the numerical algorithm is designed. Numerical experiments on the real-data of SAR images show that our novel method can reduce the noise in homogeneous areas especially speckle noise efficiently, preserve the structural feature, especially edges and textures and improve the resolution at the same time. Visually, the result of the proposed method is obviously improved.
A data transmission method between the ROS-based robot and the industrial controller
Authors: Zou Jun , Chen Zhuoxian , Zhou Cheng , Li Zhigang
Published: September 2021

Aiming at the problems of low code reusing rate and inability to share communication content amoung ROS Nodes when a ROS-based robot communicates with the industrial controller, a data transmission method based on Modbus protocol and ROS service is proposed. In this method, the program responsible for communicating with the industrial controller and the program executing the robot task are encapsulated in different ROS Nodes, using the cross-process function call of ROS Service communication to realize data sharing among multiple Nodes, thereby reducing the coupling of the system and improving the code reusing rate. Finally, the feasibility of the method is verified by a robot mechanical protection system, which provides a method for the communication between the ROS-based robot and the industrial controller.
Design Simulation and Structure Optimization of Plunger Assembly Closing
Authors: Qiao Weizhi , Wang Zhenyu , Gao Xiang , Liu Xiaochao , Qiu Zhongyi , Hou Yanze , Chen Chong
Published: September 2021

Hydraulic motors and pumps are the core components in hydraulic systems. The plunger assembly is a key component for the realization of the function of the axial piston pump and motor. The coupling between the slipper and the plunger body is completed through the closing process. With the application of computational science and finite element technology, DEFORM-3D metal forming process simulation is used to establish the corresponding closing device model of the plunger assembly. Through simulation, we analyze the change law of metal flow during plastic deformation process, and carry out structural optimization design based on the simulation results. We found that the closing is completed under the appropriate cone angle and distance line of the shoe, the quality is relatively uniform, and there is no closing defects such as metal flow overflow and cracks. The pull-off force and the clearance value after rolling can meet the design requirements. This method not only can effectively shorten the product verification cycle and reduce the cost, but also can reduce the defects of the finished product and improve the yield rate, providing a new way for the design of the closing structure and closing model of the plunger assembly.
Design of Hardware-In-The-Loop Simulation System for UAV Braking System on Electromechanical Actuator
Authors: Ji Xu , Zhang Wei , Liu Shanwu , Yang Jian , Li Weiwei
Published: September 2021

In the field of unmanned aerial vehicle(UAV), the electric braking system of UAV using electromechanical actuator is applied more and more widely due to its good safety, high reliability, light weight, small size and other characteristics. In order to realize the product development and performance test of the UAV electric braking system, a hardware-in-the-loop simulation platform is designed in this paper. The simulation platform for UAV electric braking system takes “Simulation model + hardware object” as the core and the design of the platform is based on TI company’s DSP28335 controller and the automatic code generation technology of MATLAB. The test results show that the simulation platform of UAV electric braking system has perfect function and reliable performance, which can provide a good research platform for the development and performance test of a certain type of UAV electric braking system.
Research on Working Process and Stability of Hydraulic Free Piston Engine
Authors: Sun Jie
Published: September 2021

This paper studies the working principle of the hydraulic free piston engine, and details the related contents of the working process of the hydraulic free piston engine. The related contents include the analysis of working state, the analysis of fuel injection characteristics, the analysis of the air exchange system, the analysis of the operating parameters, the working process in the cylinder, etc. The stability of the hydraulic free piston engine is studied by establishing a nonlinear model. Based on this, the stability control strategy is developed, which aims to accumulate reliable experimental data and lay a good application foundation for developing the dynamic control of hydraulic free piston engine in working process.
Effect of initial chirp for input pulse on supercontinuum generation
Authors: Liu Weici
Published: September 2021

The generation of supercontinuum spectrum is a very complex nonlinear process. Based on the nonlinear Schrodinger equation (NLSE), the effect of initial chirp on supercontinuum generation is numerically studied by split-step Fourier (SSF) method. The positive chirp and negative chirp have different effects on the supercontinuum generation. The results show that the energy distribution of supercontinuum spectrum can be improved by selecting appropriate chirp value.
Research on Load-Carrying Capacity of Loader Transmission Oil Based on Driving Axle Bench Test
Authors: Zhen Penghou , An Haizhen , Chen Li , Liu Min
Published: September 2021

The drive axle of loader is often in the state of low speed and high torque when it works, the tooth surface contact pressure is large, the tooth surface load is high, and the oil needs to have good load-carrying capacity. However, the bench test used to evaluate the load-carrying capacity of the drive axle oil adopts the drive rear axle of the truck, and the test conditions are different from the actual working conditions of the drive axle of the loader. In this paper, based on the actual working conditions of the loader drive axle into the test parameters, the bench test of simulated working conditions is carried out, and the load-carrying capacity of the oil is evaluated according to the changes of the oil performance parameters and the tooth surface damage. The results show that the established bench test method can effectively investigate the load-carrying capacity of the oil and provide support for the selection of oil in transmission system.
The Influence of Attack Angle on Projectile Trajectory and Fuze in Oblique Penetration
Authors: Shi Huifa , Ma Shaojie , Li Feiyin , Wei Jian , Tang Tong
Published: September 2021

Oblique deep penetration is a common form of projectile penetration into the target. In view of the fact that most of the research work is focused on the trajectory of vertical penetration, the trajectory and law of oblique penetration are discussed in this paper. This paper studies the impact of different initial angles of attack on projectile trajectory and fuze impact in oblique penetration by simulating projectile penetrating target with LS DYNA software. The results show that with the increase of attack angle, the deflection of trajectory is more obvious, the penetration depth is smaller, and the impact acceleration amplitude of fuze is larger. The research content of this paper provides a reference for oblique penetration of concrete target and impact performance of fuze, and is of great significance for the construction and protection of underground fortifications.
Design and simulation of magnetic adsorption System for 3D curved surface mobile Robot
Authors: Hu Jing , Ren Jing , Liao Guomin , Hu Guichuan
Published: September 2021

With the deepening of intelligent manufacturing applications, 3D curved surface mobile robots need to be developed to meet more and more practical engineering requirements. And the adsorption system is the key part of 3D curved surface mobile robot to overcome the gravity of the robot itself. Firstly, the relationship between adsorption force and inclination angle was calculated on the basis of mechanical characteristics. Secondly, we simulated the magnetic adsorption situation and acquired the relation curves of the adsorption force. Finally, the structure size and adjustment scheme of the magnetic adsorption system were determined according to the simulation results.
Research on Layout of Hoisting Points and Control of Hoisting Deformation of Large Stereo Garage Block
Authors: Li F. , Xiang Z.Q. , Wang J. , Zhang B.S.
Published: September 2021

This paper takes the dock hoisting technology of the large stereo garage block of 7800PCTC (Pure Car and Truck Carrier, PCTC) as research object. Due to the needs of loading vehicles, this kind of block has large structural size and weight, and the lack of vertical and horizontal bulkhead support in the middle, resulting in weak overall structural strength and structural instability and deformation during hoisting. Firstly, according to the hoisting process principle, three layouts of hoisting points are formulated, and the best hoisting points layout scheme is selected through FE (Finite Element, FE) simulation analysis. After analysing the deformation and structural strength of the section, a targeted temporary strengthening scheme is proposed according to the analysis results. The strengthened FE calculation results show that, the stress concentration and excessive structural deformation under the selected layout scheme are effectively controlled. The calculation results provide a strong guarantee for the hoisting in the dock loading stage.
Design of a Control System of Poplar and Willow Catkins Collection Device
Authors: JI Liqin , Zhang Zhengyi , Xie Pengfei , Chen Chao , Lin Manyu
Published: September 2021

The device that can collect poplar and willow catkins is designed to solve the environmental pollution caused by flying willow catkins and to affect people’s health in the spring. The article first conducts the background analysis, then gives the device design scheme, then completes the control system hardware design, software design, and finally designs a highly automatic and energy-efficient willow catkins automatic collection and control device for people.
Structure Design of Surrounding Tree-climbing and Pruning Robot
Authors: Yang Xi , Wang Jichen , Yan Mengxuan , Fan Shan
Published: September 2021

Tree pruning is a very important work in forestry production, which plays an important role in the growth and lumber of trees. In the general environment of automatic production of machinery, the market urgently needs a robot that can realize pruning work to replace a large amount of manual labor and increase the economic benefits of forests. In this paper, a tree-climbing and pruning robot with simple operation and automatic climbing function suitable for trimming a variety of trees is designed. The climbing mechanism of the robot adopts an enveloping wheel climbing structure, and the wheels are installed obliquely to achieve spiral ascent. The pruning mechanism adopts a combination of a mechanical arm and a saw blade, which can change the pruning method according to actual work requirements.
Study on the Characteristics of Mid-Infrared Supercontinuum
Authors: Liu Weici
Published: September 2021

Supercontinuum is widely used in spectroscopy, optical communication system, national defense security, biomedicine and other fields because of its wide spectrum and high coherence. Mid infrared laser have important value and application prospects in many fields, such as spectral analysis, remote sensing technology, space communication, military medical treatment. In this paper, the characteristics of mid-infrared supercontinuum with different distance, different incident pump power and different initial pulse width, are studied by split-step Fourier method (SSFM) based on nonlinear Schrodinger equation (NLSE).
Study on the buffering properties of composites during high-speed penetration
Authors: Chen Zhipeng , Li Haojie , Yang Benqiang
Published: September 2021

In order to solve the problems of heavy overload, poor buffer performance of cushion and low reliability of fuze in high-speed penetration process of the projectile, this paper proposes a composite structural cushion using foamed aluminum and rubber. Through the establishment of the projectile model with different material cushions, the Ls-dyna software is used to simulate the high-speed penetration process and analyze the fuze acceleration curve. The results show that the composite cushion has a significant buffering effect in the process of high-speed penetration, which can reduce the impact overload of fuze and improve the reliability of fuze.
Performance Analysis of Sparse Array Designed by Improved Density-Tapered Method
Authors: Tian Jiahao , Xu HanTao , Cao LaiBao
Published: September 2021

The density-tapered method is a method to simulate amplitude weighting of full array by using the density of antenna element. However, the probability of the existence and non-existence of the element is 0 and 1 respectively, which makes the performance of the side lobe level of the pattern worse than that of the amplitude weighting of full array. In this paper, by improving the density-tapered method, gradual and interdependent density-tapered method is proposed to realize the design of sparse linear array, and the simulation experiments are carried out to compare and analyze the performance of peak side lobe level. The experimental results show that the improved density-tapered method can further reduce the side lobe level of the pattern.
Hydraulic Performance of Water Inlet Device in Ship Scoop Cooling System
Authors: Lao Xingsheng , Dai Tianqi , Gong Xian , Zhang Wei , Li Bangming , Wang Wei
Published: September 2021

The scoop cooling system is widely used in advanced ships which usually requires a water inlet device protruding out of the board. The structure of the water inlet device not only determines the cooling water flow into the system, but also affects the additional resistance of the hull. The ratio of the static pressure difference between windward side of the device and the environment and the dynamic pressure head of the cooling water entering the flow channel is defined as the scoop lift head. The scoop lift head and additional resistance are used to describe the hydraulic performance of the water inlet device of the scoop cooling system, and a theoretical analysis method for the performance of the water inlet device of the scoop cooling system is proposed. The actual ship parameters are used to verify the scoop cooling capability and drag resistance characteristics of the water inlet device.