bluuebunny/crossref_metadata_2025 huggingface dataset:
Friedmann cosmology with decaying vacuum density in Brans–Dicke theory
Authors: Singh C. P. , Solà Peracaula Joan
Published: October 2021

In this paper, we study Friedmann cosmology with time-varying vacuum energy density in the context of Brans–Dicke theory. We consider an isotropic and homogeneous flat space, filled with a matter-dominated perfect fluid and a dynamical cosmological term $$\varLambda (t) $$

Λ
(
t
)

, obeying the equation of state of the vacuum. As the exact nature of a possible time-varying vacuum is yet to be found, we explore $$\varLambda (t)$$

Λ
(
t
)

given by the phenomenological law $$\varLambda (t)=\lambda +\sigma H$$

Λ
(
t
)
=
λ
+
σ
H

, where $$\lambda $$
λ
and $$\sigma $$
σ
are positive constants. We solve the model and then focus on two different cases $$\varLambda _{H1}$$

Λ

H
1

and $$\varLambda _{H2}$$

Λ

H
2

by assuming $$\varLambda =\lambda $$

Λ
=
λ

and $$\varLambda =\sigma H$$

Λ
=
σ
H

, respectively. Notice that $$\varLambda _{H1}$$

Λ

H
1

is the analog of the standard $$\varLambda $$
Λ
CDM, but within the Brans–Dicke cosmology. We find the analytical solution of the main cosmological functions such as the Hubble parameter, the scale factor, deceleration and equation of state parameters for these models. In order to test the viability of the cosmological scenarios, we perform two sets of joint observational analyses of the recent Type Ia supernova data (Pantheon), observational measurements of Hubble parameter data, Baryon acoustic oscillation/Cosmic microwave background data and Local Hubble constant for each model. For the sake of comparison, the same data analysis is performed for the $$\varLambda $$
Λ
CDM model. Each model shows a transition from decelerated phase to accelerated phase and can be viewed as an effective quintessence behavior. Using the model selection criteria AIC and BIC to distinguish from existing dark energy models, we find that the Brans–Dicke analog of the $$\varLambda $$
Λ
-cosmology (i.e. our model $$\varLambda _{H1}$$

Λ

H
1

) performs at a level comparable to the standard $$\varLambda $$
Λ
CDM, whereas $$\varLambda _{H2}$$

Λ

H
2

is less favoured.
Charged gravastars in modified Gauss–Bonnet gravity
Authors: Bhatti M. Z. , Yousaf Z. , Ashraf T.
Published: October 2021

This work probes the influence of charge field on the unique stellar structure, regarded as gravastar, under the corrections of [Formula: see text] theory, i.e. [Formula: see text] theory, where [Formula: see text] is named as Gauss–Bonnet invariant. The gravastar has also been recognized as an alternate candidate of black hole structure and is illustrated by three distinct regions termed as (1) the exterior (2) the intermediate thin shell (3) the interior domain. We discussed the mathematical solutions for each of three regions separately with the assistance of different equation-of-states (EoS). The exterior charged vacuum domain is expressed by the Reissner–Nordström solution. The central region is illustrated by the EoS, i.e. a positive pressure of ultra-relativistic matter is equal to the energy density. Whereas, the interior domain reflects that the negative pressure is equal to energy density and manifests a non-attractive force over the central spherical shell. We deduce that in the context of [Formula: see text] theory, the nonsingular charged model with distinct physical features, such as energy, length, entropy, is physically viable and consistent.
PERFORMANCE TEST AND HEAT RESISTANCE OF PHYSICAL AND CHEMICAL COATED IRON OXIDE BLACK PIGMENT
Authors: YAN KE , BAO CHUNYAN , WANG ZHENG
Published: October 2021

The current development strategy of inorganic pigments is to develop technologies, such as high coloring ability, low oil absorption, easy dispersion, heat resistance, and nontoxicity. As the largest colored inorganic pigments, iron oxide pigments are widely used in building materials, coatings, rubber, plastics, paint, etc. In this paper, black iron oxide pigment was used as the carrier, and alumina substance was used as the support. Precipitation method was used to synthesize the aluminum oxide-coated iron oxide black composite pigment under different experimental conditions, and the coated iron was studied by XRD, SEM and TEM characterization methods. The structure of the black pigment, discuss the influence of the coating temperature, reaction pH, coating method, neutralizing acid and other factors on the microstructure of the composite material and the performance of the pigment. The experimental results show that, through co-current coating, the temperature of the reaction system of 80∘C and the reaction pH of 10–11 are the best parameters for coating. The oil absorption, tinting power, hiding power and dispersion power of the coated iron black were tested, and the performance of the iron black pigment was greatly improved after the coating. The heat resistance and light fastness of iron black were tested through the color difference change experiment. The experimental results showed that the heat resistance and light fastness of iron black pigment showed good performance after coating.
Abnormal Homocysteine Metabolism: An Insight of Alzheimer’s Disease from DNA Methylation
Authors: Pi Tingting , Liu Bo , Shi Jingshan
Published: October 2021

Alzheimer’s disease (AD) is a chronic neurodegenerative disease in the central nervous system that has complex pathogenesis in the elderly. The current review focuses on the epigenetic mechanisms of AD, according to the latest findings. One of the best-characterized chromatin modifications in epigenetic mechanisms is DNA methylation. Highly replicable data shows that AD occurrence is often accompanied by methylation level changes of the AD-related gene. Homocysteine (Hcy) is not only an intermediate product of one-carbon metabolism but also an important independent risk factor of AD; it can affect the cognitive function of the brain by changing the one-carbon metabolism and interfering with the DNA methylation process, resulting in cerebrovascular disease. In general, Hcy may be an environmental factor that affects AD via the DNA methylation pathway with a series of changes in AD-related substance. This review will concentrate on the relation between DNA methylation and Hcy and try to figure out their rule in the pathophysiology of AD.
An Automatic Planning-Based Attack Path Discovery Approach from IT to OT Networks
Authors: Wang Zibo , Zhang Yaofang , Liu Zhiyao , Wei Xiaojie , Chen Yilu , Wang Bailing
Published: October 2021

With the convergence of IT and OT networks, more opportunities can be found to destroy physical processes by cyberattacks. Discovering attack paths plays a vital role in describing possible sequences of exploitation. Automated planning that is an important branch of artificial intelligence (AI) is introduced into the attack graph modeling. However, while adopting the modeling method for large-scale IT and OT networks, it is difficult to meet urgent demands, such as scattered data management, scalability, and automation. To that end, an automatic planning-based attack path discovery approach is proposed in this paper. At first, information of the attacking knowledge and network topology is formally represented in a standardized planning domain definition language (PDDL), integrated into a graph data model. Subsequently, device reachability graph partitioning algorithm is introduced to obtain subgraphs that are small enough and of limited size, which facilitates the discovery of attack paths through the AI planner as soon as possible. In order to further cope with scalability problems, a multithreading manner is used to execute the attack path enumeration for each subgraph. Finally, an automatic workflow with the assistance of a graph database is provided for constructing the PDDL problem file for each subgraph and traversal query in an interactive way. A case study is presented to demonstrate effectiveness of attack path discovery and efficiency with the increase in number of devices.
Congestion Attack Detection in Intelligent Traffic Signal System: Combining Empirical and Analytical Methods
Authors: Xiang Yingxiao , Niu Wenjia , Tong Endong , Li Yike , Jia Bowei , Wu Yalun , Liu Jiqiang , Chang Liang , Li Gang
Published: October 2021

The intelligent traffic signal (I-SIG) system aims to perform automatic and optimal signal control based on traffic situation awareness by leveraging connected vehicle (CV) technology. However, the current signal control algorithm is highly vulnerable to CV data spoofing attacks. These vulnerabilities can be exploited to create congestion in an intersection and even trigger a cascade failure in the traffic network. To avoid this issue, timely and accurate congestion attack detection and identification are essential. This work proposes a congestion attack detection approach by combining empirical prediction and analytical verification. First, we collect a range of traffic images that correspond to specific traffic snapshots which are vulnerable to potential data spoofing attacks. Based on these traffic images, an improved generative adversarial network is trained to predict whether a forthcoming attack will cause congestion with a high probability. Meanwhile, we define a group of traffic flow features. After exploring features and conducting a thorough analysis, a TGRU (tree-regularized gated recurrent unit)-based approach is proposed to verify whether congestion occurs. When we find a possible attack that can cause congestion with high probability and subsequent traffic flows also prove congestion, we can say there is a congestion attack. Thus, we can realize timely and accurate congestion attack detection by integrating empirical prediction and analytical verification. Extensive experiments demonstrate that our approach performs well in congestion attack detection accuracy and timeliness.
Transversus Abdominis Plane (TAP) Block: A Comparative Study between Levobupivacaine versus Levobupivacaine plus Ketamine in Abdominoplasty
Authors: Mansour Radwa F. , Afifi Mohamed A. , Abdelghany Mohamed S.
Published: October 2021

Purpose. We conducted this study to explore the hypothesis that the addition of ketamine to levobupivacaine in ultrasound-guided Transversus Abdominis Plane (TAP) block would result in a better and prolonged duration of postoperative analgesia for patients undergoing abdominoplasty. Material and Methods. This randomized prospective study was conducted on 50 patients who were scheduled for abdominoplasty. TAP block was performed bilaterally for all patients either with levobupivacaine 0.5% 15 ml plus ketamine 0.5 mg/kg in a total volume of 20 ml in the LK group (n = 25) or with levobupivacaine 0.5% 15 ml plus 5 ml normal saline in a total volume of 20 ml in the L group on each side. Results. Visual analogue scale (VAS) was significantly lower in the LK group in resting condition at 6, 12, and 16 h postoperatively compared to the L group. On movement, the VAS was significantly lower at 4, 6, 8, 12, 16, and 24 h postoperatively in the LK group compared to the L group. The time for first rescue analgesia was longer in the LK group (18.7 ± 4.8 h) than that in the L group (6.5 ± 2.4 h) with the reduced total amount of rescue morphine in the LK group (1.14 ± 2.2 mg) versus the L group (5.86 ± 3.6 mg). Only six patients in the LK group requested rescue morphine, whereas nineteen patients requested rescue morphine in the L group. Conclusions. In TAP block, adding ketamine 0.5 mg/kg enhanced the analgesic efficacy of levobupivacaine 0.5% in patients undergoing abdominoplasty and reduced the required analgesics postoperatively.
Correlation between Palpitations below the Heart in Traditional Chinese Medicine and Autonomic Nerve Function Based on Heart Rate Variability: A Case-Control Study
Authors: Song Chengcheng , Chen Kelong , Wu Ziqian , Liu Wei , Chen Ling , Zhu Wenzong
Published: October 2021

Objective. To explore the autonomic nerve rhythm and the correlation between palpitations below the heart (PBTH) and autonomic nerve function in patients with PBTH based on heart rate variability (HRV). Methods. The outpatients or ward patients of Wenzhou Hospital of Traditional Chinese Medicine were collected and divided into two groups: the PBTH group and the normal group. The HRV of each group was detected. Single-factor statistical methods, Spearman correlation analysis, and logistic regression were used to describe and analyze the rhythm and characteristics of autonomic nerves in patients with PBTH and the correlation between PBTH and autonomic nerve function. Results. (1) In the comparison of HRV in different time periods in the same group, the SDNN, RMSSD, pNN50, TP, and HF in the PBTH group at night were significantly higher than those in the daytime (

P
<
0.01

), while the LF/HF ratio was significantly lower than that in the daytime (

P
<
0.01

). (2) In the comparison of HRV between the two groups in the same time period, the RMSSD and pNN50 of the PBTH group during the daytime period were significantly higher than those of the normal control group (

P
<
0.05

), and the LF/HF was significantly lower than that of the normal group (

P
<
0.05

). (3) In the Spearman correlation analysis, PBTH was significantly correlated with RMSSD, pNN50, and LF/HF ratio in the daytime period, with correlation coefficients of 0.424, 0.462, and −0.524, respectively (

P
<
0.05

). (4) Logistic regression analysis showed that the decrease of LF/HF ratio during the daytime period was an independent risk factor for PBTH in TCM (OR = 0.474, 95% CI: 0.230–0.977,

P
<
0.05

). Conclusions. The changes in parasympathetic nerve function in patients with PBTH have a circadian rhythm, which is characterized by increased activity during the nighttime. At the same time, the autonomic nerve activity of people with PBTH during the daytime is unbalanced, and the decrease of LF/HF ratio during the day is an independent high risk factor for PBTH.
Global Exponential Stability of a Discrete-Time Rayleigh System with Delays
Authors: Shen Bangyu
Published: October 2021

This paper deals with the problem of global exponential stability for a discrete-time Rayleigh system with delays. By using the mathematical induction method, some sufficient conditions are proposed for the global exponential stability of the discrete-time Rayleigh system. Finally, a numerical example is given to illustrate the effectiveness and application of the obtained results.
Quality of Services Based on Intelligent IoT WLAN MAC Protocol Dynamic Real‐Time Applications in Smart Cities
Authors: Alnazir Abbas , Mokhtar Rania A. , Alhumyani Hesham , Ali Elmustafa Sayed , Saeed Rashid A. , Abdel-khalek S.
Published: October 2021

The future directions and challenges for 6G‐enabled wireless communication for IoT applications are mainly focused on quality of service (QoS). The selection criteria of mobility management (MM) protocol are mainly the total duration of the delay and packet loss rate during the MM procedure. This is called intelligent handover (IH) to designate a relay with a minimum delay. To solve the problem of handover, media access control (MAC) protocols are used to provide an intelligent protocol for QoS in real‐time application in mobility. Moreover, changing the parameter to find the best protocol for mobile stations in WLAN is a good choice. This paper proposed a new QoS structure for the point coordination function that is based on a new intelligent enhanced distribution coordination function that suites with dynamic real‐time applications and services. The paper addresses the distributed coordination function (DCF) with QoS‐based intelligent mobility management in stations and other scenarios with enhanced distribution coordination function (EDCF) to find the result of throughput, retransmission attempts, delay, and data droop. In this paper, the remote topology comprises a few remote stations and one base station within the remote LAN. All remote stations are found that each station can distinguish a transmission from any other station, and there is portability within the proposed intelligent framework.
Performance Investigation of Tempered Glass-Based Monocrystalline and Polycrystalline Solar Photovoltaic Panels
Authors: Huot Mardy , Kumar Laveet , Selvaraj Jeyraj , Hasanuzzaman Md , Rahim Nasrudin Abd
Published: October 2021

Solar photovoltaic (PV) converts sunlight into electricity and is an appropriate alternative to overcome the depletion of conventional fuels and global warming issues. The performance of a PV panel may vary with respect to PV cell technology, fabrication methods, and operating conditions. This research aims at performing an experimental study to investigate the electrical performance of novel tempered glass-based PV panels using two different types of solar cells: monocrystalline and polycrystalline. Tempered glass-based panels are modified forms of commercial PV panels, in which ethylene-vinyl acetate (EVA) and Tedlar are not utilized. This new fabrication method was carried out in this research. Real-time data recordings regarding the PV electrical characteristics (

I

-

V

curve) and solar irradiance were conducted under Malaysian weather conditions on clear sunny days. Results indicated that, at solar irradiance of 900 W/m2, the outputs from the fabricated polycrystalline and monocrystalline PV panels were 67.4 W and 75.67 W, respectively. However, at the highest average solar irradiance (634.61 W/m2), which was obtained at 12:30 PM, the outputs from both panels were 47.87 W and 54.89 W. An

I

-

V

curve was obtained for the real-time weather. The electrical efficiencies of the two PV panels were analyzed to be 10.54% and 12.23%.
Roles of Alkaloids from Medicinal Plants in the Management of Diabetes Mellitus
Authors: Adhikari Bikash
Published: October 2021

Medicinal plants play a fundamental part in health sectors via the management of different infectious diseases because of their wide plenitude wellspring of bioactive phytochemicals. Research activities on them have got attention throughout the world in the present days in search of low-cost and safe compounds for the management of diabetes. This is the literature-based analysis of alkaloids from medicinal plants in preventive or treatment approaches to diabetes. The most abundant and diversified group of secondary metabolites, i.e., alkaloids, show antidiabetic activity through the inhibition of enzymes (α-amylase, α-glucosidase, aldose reductase, dipeptidyl peptidase-IV, and protein tyrosine phosphatase-1B); inhibition of advanced glycation end products; increment of insulin secretion and its sensitivity; enhancement of glucose uptake; and their antioxidant ability. The study is useful for the examination of dynamic alkaloids for the advancement of a new medication for mankind.
Pareidolia in Parkinson’s Disease and Multiple System Atrophy
Authors: Kurumada Kentaro , Sugiyama Atsuhiko , Hirano Shigeki , Yamamoto Tatsuya , Yamanaka Yoshitaka , Araki Nobuyuki , Yakiyama Masatsugu , Yoshitake Miki , Kuwabara Satoshi
Published: October 2021

Pareidolia is a visual illusion of meaningful objects that arise from ambiguous forms embedded in visual scenes. Previous studies showed that pareidolias are frequently observed in patients with Parkinson’s disease (PD) as well as dementia with Lewy bodies. However, whether pareidolias are useful for differentiating PD from other neurodegenerative parkinsonism disorders including multiple system atrophy (MSA) is unclear. The noise pareidolia test (NPT) was performed in 40 and 48 patients with PD and MSA, respectively. A receiver operating characteristic (ROC) curve analysis was used to evaluate sensitivity and specificity. Results of neuropsychological tests were also compared between patients with PD with and without pareidolias. Visual hallucinations were present in none of the subjects. Pareidolic response in the NPT was observed in 47.5% and 18.8% of patients with PD and MSA, respectively. The number of pareidolic responses in patients with PD was significantly larger compared with patients with MSA (

P
=
0.001

). ROC curve analyses showed the sensitivity and specificity at 33% and 98%, respectively. Among patients with PD, those with pareidolias demonstrated higher State-Trait Anxiety Inventory-state (

P
=
0.044

) and State-Trait Anxiety Inventory-trait (

P
=
0.044

) than those without pareidolias. Pareidolias can be found in patients with PD without visual hallucinations, and the pareidolia test may be a highly specific test for differentiating PD from MSA. Thus, anxiety may be associated with pareidolias in patients with PD.
Correlation Analysis of Huayu Tongmai Decoction Intervention and Prognosis Indexes of Patients with Carotid Atherosclerosis
Authors: Cheng Guangqing , Yan Xiaoni , Wang Fengmeng , Chen Chao
Published: October 2021

Background. Carotid atherosclerosis (CAS) is a common disease which seriously threatens the health of senile patients. The studies have indicated that traditional Chinese medicine (TCM) may effectively improve the symptom of CAS, while the therapeutic effect of Huayu Tongmai decoction on CAS remains unclear. Thus, this study aimed to explore the correlation between traditional Chinese medicine Huayu Tongmai decoction intervention and prognosis indexes of patients with CAS. Methods. Ninety CAS patients admitted to Zibo TCM-Integrated Hospital from September 2018 to September 2020 were selected as the research object and randomly divided into the control group and the observation group according to the male-female ratio of 1 : 1. Patients in the control group accepted the atorvastatin intervention, and on this basis, patients in the observation group were further intervened with TCM Huayu Tongmai decoction. Before and after treatment, patients’ levels of total cholesterol (TC), triglyceride (TG), and low-density lipoprotein cholesterol (LDL-C) were measured by the enzyme photometric colorimetry; hypersensitive c-reactive protein (hs-CRP) levels were measured by the ELISA method; nitric oxide (NO) levels were measured by the nitrate reductase assay and endothelin-1 (ET-1) levels were measured by radioimmunoassay; and the right and left carotid internal diameter (CAD), intima-media thickness (IMT), and plaque volume were measured by carotid ultrasonography. Results. The TC, TG, and LDL-C levels significantly decreased in patients compared to those before intervention; compared with the control group, patients who accepted Huayu Tongmai decoction combined with atorvastatin saw more significant improvement in their blood lipid indexes (

P
<
0.01

); after intervention, patients’ hs-CRP and ET-1 levels dropped significantly while the NO level rose remarkably, and between the two groups, the improvement in levels of hs-CRP, ET-1, and NO of patients in the observation group was significantly better (

P
<
0.01

); it was concluded from the imaging diagnosis results that compared with using atorvastatin alone, the combined intervention could better improve patients’ CAD, IMT, and plaque volume. Conclusion. Huayu Tongmai decoction can effectively improve patients’ blood lipid, reduce inflammatory response, enhance levels of relevant regulatory factors of CAS, and alleviate the symptoms.
Probabilistic Analysis of Wheel Loader Failure under Rockfall Conditions Based on Bayesian Network
Authors: Feng Zhenmin , Huang Dongmei , Li Zhian , Li Rui , Sun Yupeng
Published: October 2021

Rockfall is one of the most serious geological hazards in mountain regions. During the rescue situations after rockfall, the wheel loader, a vital type of modern engineering mechanism, plays an important role in relieving the obstruction of the catastrophic site. Increasing the reliability of the wheel loader during the rescue situation is quite important. This study aims to build a fault diagnosis model based on Bayesian network (BN) to diagnose the probability and path of the fault occurrence in the wheel loader during a rockfall disaster. Meanwhile, to reduce the influence of subjective factors, the fuzzy set theory is introduced into BN. The result showed that the probability of failure of the wheel loader under rockfall disaster is 13.11%. In addition, the key cause of the failure of the wheel loader under the rockfall disaster is the malfunction of mechanical parts. The probability of mechanical component failures in this case is as high as 88%, while the probability of human error is 6%. The research results not only show the ability of the BN to incorporate subjective judgment but also can provide a reference for fault diagnosis and risk assessment of wheel loaders under rockfall disaster conditions.
Design of Multiple Dependent State Sampling Plan Application for COVID‐19 Data Using Exponentiated Weibull Distribution
Authors: Gadde Srinivasa Rao , Fulment Arnold K. , Peter Josephat K.
Published: October 2021

The proposed sampling plan in this article is referred to as multiple dependent state (MDS) sampling plans, for rejecting a lot based on properties of the current and preceding lot sampled. The median life of the product for the proposed sampling plan is assured based on a time‐truncated life test, when a lifetime of the product follows exponentiated Weibull distribution (EWD). For the proposed plan, optimal parameters such as the number of preceding lots required for deciding whether to accept or reject the current lot, sample size, and rejection and acceptance numbers are obtained by the approach of two points on the operating characteristic curve (OC curve). Tables are constructed for various combinations of consumer and producer’s risks for various shape parameters. The proposed MDS sampling plan for EWD is demonstrated using the coronavirus (COVID‐19) outbreak in China. The performance of the proposed sampling plan is compared with the existing single‐sampling plan (SSP) when the quality of the product follows EWD.
Therapeutic Mechanism and Clinical Observation of Traditional Chinese Medicine Combined with Interventional Recanalization for Tubal Infertility
Authors: Liu Can , Qiu Hao , Huang Rong , Chai Hua , Yuan Guibin , Shan Shihang
Published: October 2021

To observe the clinical effect of traditional Chinese medicine (TCM) combined with interventional recanalization therapy in the treatment of tubal obstructive infertility, first, different treatment approaches were used on rabbits, and transmission electron microscopy (TEM) indicated that interventional recanalization combined with TCM can significantly ameliorate the pathological condition of the fallopian tube after treatment. Moreover, ELISA disclosed that the treatment could significantly reduce the levels of interleukin-1β (IL-1β), interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α) and increase the expression of interleukin-10 (IL-10), which demonstrated that TCM therapy can help against inflammation of the fallopian tubes. PCR array analysis revealed that BMP4, BMPR1A, SMAD2, SMAD3, SMAD4, and KLF10 expressions were upregulated, and SMAD7 expression was downregulated, proving that combined treatment could influence gene expression in the TGF-β family and further regulate the secretion of proteins in SMADs. In addition, a clinical study recorded the fallopian tube patency rate of 165 patients after 12 months. The recanalization rates in the two groups were 81.9% and 53.1%, with the higher rates in the combined medicine enema group. All these findings implied that interventional recanalization combined with TCM preparation has a stronger effect. The mechanism probably involves effects on the expression of genes in the TGF-β/SMAD and BMP/SMAD signaling pathways, with simultaneous regulation of inflammatory factors, thereby improving the ovarian environment and increasing pregnancy rates.
Analysis of the Reactivity of Aspirin and Clopidogrel and Its Influencing Factors in Patients with Coronary Heart Disease at High Altitude
Authors: Chang Rong , Wu Jinchun , Zhang Xiaofei , Ye Yi , Zhou Wenqin , Liu Yanmin
Published: October 2021

Objective. To evaluate the efficacy of dual-antiplatelet treatment (DAPT) in patients with coronary heart disease (CHD) at high altitude by using thrombelastogram (TEG) and to analyze the related biochemical factors affecting drug reactivity. Methods. Totally 118 CHD patients who admitted to the Qinghai People’s Hospital from September 2019 to September 2020 were enrolled in the group. Those people have lived in Qinghai for a long time. Seven days after DAPT, venous blood was collected on an empty stomach in the early morning of the next day; blood routine, coagulation function, and biochemical items were tested. Thrombelastogram (TEG) was used to draw curves to calculate platelet, coagulation and fibrinolysis functions, and drug inhibition rate. Patients were divided into the aspirin resistance (AR) group, clopidogrel resistance (CR) group, dual-antiplatelet drug resistance (DAR) group, and drug-sensitive group according to different inhibition rates. The drug efficacy was analyzed, and the clinical data, biochemical indexes, and TEG parameters of each group were compared to identify the risk factors of drug resistance. Results. Those 118 CHD patients at high altitude were incorporated into the study, ranging from 38 to 84 years of age, including 81 males (68.64%) and 37 females (31.36%). The platelet function and coagulation-fibrinolysis function were detected by TEG, and MATHROMBI, MAADP, and MAAA were higher than the reference range. There were 82 cases (69.49%) of drug resistance, 36 cases (32.53%) of drug sensitivity, 17 cases (14.41%) of AR alone, and 16 cases (12.71%) of CR alone. There was no significant difference in age, gender, BMI, oxygen saturation, TG, GFR, and history of diabetes and hypertension between ACS and CCS groups (

P
>
0.05

). PLT and FIB in the ACS group were higher than those in the CCS group, and the difference was statistically significant (

P
<
0.05

). In addition, MATHROMBIN, MAFIBRIN, E, A, A30, and coagulation composite index were also higher than those in the CCS group, with a statistically significant difference (

P
<
0.05

). Univariate analysis and logistic regression analysis suggested that age, HbA1c, FBG, and diabetes were the main factors of drug resistance. Conclusion. Antiplatelet drugs aspirin and clopidogrel resistance are associated with increased age, elevated HbA1c and FBG, and diabetes. Therefore, it is necessary to take reasonable treatment measures based on the actual situation of patients.
The Influence of Multimedia Input Mode Based on Complex System Discrete Model on College Students’ English Ability
Authors: Wang Xiaoge , Zhao Weihong , Xu Yuanyuan
Published: October 2021

With the rapid development of the Internet, the amount of data increases sharply. In this network age, data have been generated, such as multimedia, social networks, and search records. Due to the generation of data, complex system discrete model technology is also widely used in all walks of life. Multimedia learning is a popular teaching mode in the world. Through the discrete model technology of the complex system, this paper deeply studies the impact of multimedia input on college students’ English ability. Because the modeling and sampling of complex systems are abstract and not fixed, approximation and control methods are adopted in discrete time, which greatly improves the reliability of the final research results. Compared with the original discrete modeling technology, this paper adds data sampling compression and assimilation technology on the basis of the original discrete modeling technology of the complex system. The results show that, by adding the technical application of controllable and observable systems, the discrete model of the whole complex system can reduce the error of the final output data. At the same time, this paper compresses and simplifies the data nodes at the microlevel. Macroscopically, it reduces the scale, especially the number of node data compression. The final result also realizes the data scale and greatly shortens the calculation time. This study has greatly improved the accuracy of the impact of multimedia on Chinese college students’ English ability in practical application.
Development and Application of Efficient Oil Displacement System for Middle‐Low Permeability and High Pour‐Point Heavy Oil Reservoirs
Authors: Ma Zhenfu , Zhang Kai , Zhao Mengjie , Liu Lu , Zhong Chao , Wang Jian
Published: October 2021

In view of the problems of low permeability, high oil viscosity and freezing point, and low productivity of single well in Luo 321 and Luo 36 blocks of Luojia Oilfield, the chemical viscosity‐reducing cold production technology was studied. By analyzing the properties of crude oil, it is concluded that the reason for high viscosity and high freezing point is the high content of asphaltene, pectin, and wax. The viscosity is mainly affected by asphaltene; the wax precipitation point and pour point are mainly affected by the wax; and the solidification point is affected by the wax and asphaltene. The treatment idea of reducing viscosity and inhibiting wax is determined. By compounding the synthetic pour point depressant POA‐VA and the viscosity reducer DBD‐DOPAMA, the effect of reducing the viscosity and freezing point of crude oil was evaluated. PD‐7 (POA‐VA 40%, DBD‐DOPAMA 50%, and P‐10C 10%) system was selected as the optimal formula. When the concentration of the system is 10%, the viscosity reduction rate reaches 95.2%; the freezing point can reduce by 10.2°C; it has good oil sample adaptability, salinity resistance, and temperature resistance; and the oil washing rate can reach more than 60%. The oil displacement system was injected into the formation by means of multiconcentration and multislug and was applied in the field of Luo 321‐2 Well. A total of 500 t of the oil displacement system was injected, and the effect of measures lasted for 400 days, with a cumulative oil increase of 883 t. It has been applied in different blocks 30 times and achieved a good field application effect.
Use of Organic and Copper-Based Nanoparticles on the Turbulator Installment in a Shell Tube Heat Exchanger: A CFD-Based Simulation Approach by Using Nanofluids
Authors: Chupradit Supat , Jalil Abduladheem Turki , Enina Yulianna , Neganov Dmitriy A. , Alhassan Muataz S. , Aravindhan Surendar , Davarpanah Afshin
Published: October 2021

Heat exchangers with unique specifications are administered in the food industry, which has expanded its sphere of influence even to the automotive industry due to this feature. It has been used for convenient maintenance and much easier cleaning. In this study, two different nanomaterials, such as Cu-based nanoparticles and an organic nanoparticle of Chloro-difluoromethane (R22), were used as nanofluids to enhance the efficiency of heat transfer in a turbulator. It is simulated by computational fluid dynamics software (Ansys-Fluent) to evaluate the Nusselt number versus Reynolds number for different variables. These variables are diameter ratio, torsion pitch ratio, and two different nanofluids through the shell tube heat exchanger. It is evident that for higher diameter ratios, the Nusselt number has been increased significantly in higher Reynolds numbers as the heat transfer has been increased in turbulators. For organic fluids (R22), the Nusselt number has been increased significantly in higher Reynolds numbers as the heat transfer has been increased in turbulators due to the proximity of heat transfer charges. At higher torsion pitch ratios, the Nusselt number has been increased significantly in the higher Reynolds number as the heat transfer has been increased in turbulators, especially in higher velocities and pipe turbulence torsions.
Difference between Internal and External Hydration of Hardened Cement Paste under Microwave Curing
Authors: Yan Guoshun , Li Jiazheng , Lin Yuqiang , Chen Xia
Published: October 2021

In order to investigate the difference between internal and external hydration of hardened cement paste under microwave curing, a comparative study on the hydration products, hydration degree, fracture morphology, and pore structure between the inner part and outer part of hardened cement paste (Φ120 mm × 120 mm) under microwave curing was carried out by XRD‐Rietveld refinement, TG‐DSC, SEM, and MIP methods. The results show that the total hydration degree of the inner part is lower at early ages, but with the hydration, there is little difference in the hydration degree between inner and outer parts at later ages. Apart from granular AFt crystal formed in the inner part of hardened cement paste, there is little difference in the fracture morphology between internal and external hydration. The total porosity of the outer part is lower than that of the inner part.
An OCaNet Model Based on Octave Convolution and Attention Mechanism for Iris Recognition
Authors: Zou Dong , Feng Jianbing , He Zhixin , Liu Liping , Zhao Meijun , Zheng Lizhong
Published: October 2021

Iris recognition refers to identifying individuals based on iris patterns, which have been widely used in security systems, such as subway security and access control attendance, because everyone has a unique iris shape. In the study, we propose an OCaNet model for the iris recognition task. First, binarized threshold segmentation is used to locate the pupil and the pupil boundary is obtained; then, the Hough transform is applied to locate the outer edge of the iris; according to the located pupil and iris, the iris area image is obtained through image segmentation; finally, the iris image is normalized to adjust each original image to the same size and corresponding position, so as to eliminate the influence of translation, scaling, and rotation on iris recognition. Second, the normalized iris images are both input into the octave convolution module and attention module. The octave convolution module is used to extract the shape and contour features of the iris by decomposing the feature map into high and low frequencies. The attention module is applied to extract the color and texture characteristics of the iris. Finally, the two feature maps are concatenated and produce a distribution of output classes. Experimental results show that the proposed OCaNet model is significantly more accurate.
A Comparison of Gaussian Process and M5P for Prediction of Soil Permeability Coefficient
Authors: Pham Binh Thai , Ly Hai-Bang , Al-Ansari Nadhir , Ho Lanh Si
Published: October 2021

The permeability coefficient (k) of soil is one of the most important parameters affecting soil characteristics such as shear strength or settlement. Thus, determining soil permeability coefficient is very crucial; however, a field test for determining this parameter is difficult, time-consuming, and expensive. In this study, soft computing methods, namely, M5P and Gaussian process (GP), for estimating the permeability coefficient were constructed and compared. The results of this paper indicate that the two soft computing algorithms functioned well in predicting k. These two methods gave high accuracy of prediction capability. The determination coefficient of M5P (R2 = 0.766) was higher than that (R2 = 0.700) of GP. This implies that the M5P model is more reliable estimation than the GP model in predicting soils’ permeability coefficient (k). This proves that applying these machine learning techniques can provide an alternative for predicting basic soil parameters, including the permeability coefficient of soil.
Effects of Plyometric Exercises versus Flatfoot Corrective Exercises on Postural Control and Foot Posture in Obese Children with a Flexible Flatfoot
Authors: Allam Hatem H. , Muhsen Alsufiany , Al-walah Mosfer A. , Alotaibi Abdulmajeed N. , Alotaibi Shayek S. , Elsayyad Lamiaa K.
Published: October 2021

Background. Obesity contributes to the acquired flatfoot deformity which in turn impairs balance. Aim. The purpose of the current study was to compare the effect of plyometric exercises with flatfoot corrective exercises on balance, foot posture, and functional mobility in obese children with a flexible flatfoot. Methods. Forty-seven children participated in the study. Their age ranged from 7 to 11 years. Participants were randomly divided into 3 groups: experimental group I (EGI), experimental group II (EGII), and the control group (CG). The EGI received plyometric exercises and the EGII received corrective exercises, 2 sessions weekly for 10 weeks. The control group did not perform any planned physical activities. The Prokin system was used to assess balance, the timed up and go test (TUG) was used to assess functional mobility, and the navicular drop test (NDT) was used to assess foot posture. Results. EGI showed significant improvement in all balance parameters, foot posture, and TUG. EGII showed improvement in the ellipse area and perimeter in addition to foot posture and TUG. Conclusion. Plyometric exercises and foot correction exercises had a positive effect on foot posture, balance, and functional mobility in obese children with flatfeet.
Obstacle Avoidance Control for Multisteering Mode of Multiaxle Wheeled Robot Based on Trajectory Prediction Strategy
Authors: Zhu Yongqiang , Zhu Junru , Zhang Pingxia
Published: October 2021

A multiaxle wheeled robot is difficult to be controlled due to its long body and a large number of axles, especially for obstacle avoidance and steering in narrow space. To solve this problem, a multisteering mode control strategy based on front and rear virtual wheels is proposed, and the driving trajectory prediction of the multiaxle wheeled robot is analyzed. On this basis, an obstacle avoidance control strategy based on trajectory prediction is proposed. By calculating the relationship between the lidar points of the obstacle and the trajectory coverage area, the iterative calculation of the obstacle avoidance scheme for the proposed steering is carried out, and the feasible obstacle avoidance scheme is obtained. The mechanical structure, hardware, and software control system of a five-axle wheeled robot are designed. Finally, to verify the effectiveness of the obstacle avoidance strategy, a Z-shaped obstacle avoidance experiment was carried out. The results confirm the effectiveness of the proposed control strategy.
Acoustic Control through Gradient Coil Design Using a Finite-Difference-Based Method for MRI
Authors: Kang Liyi , Xia Ling
Published: October 2021

An acoustic control scheme is proposed in this paper through the process of gradient coil design for magnetic resonance imaging (MRI). With a finite-difference-based method, the stream function and coil displacement caused by fast gradient switching can be unified by a simplified momentum equation, which can be incorporated into the conventional gradient coil design. A three-dimensional transverse gradient coil with an edge-connected cylindrical structure is used as a design example to verify the proposed design method. In addition, an acoustic model is established to simulate the sound pressure level (SPL).In the model, two hemispherical air volumes are added flush with the ends of the cylindrical main magnet to mimic the free propagation of sound waves on the boundaries. The simulation results show that by optimizing coil displacement, the overall SPL can be attenuated by 4 dB over the frequency range from 0 to 3000 Hz with the displacement reduced by about 50%, at the cost of a figure of merit (FOM) loss by about 8%. Therefore, the proposed acoustic control scheme can be used as a complement to conventional acoustic control methods for further noise reduction.
Impact of Ramped Concentration and Temperature on MHD Casson Nanofluid Flow through a Vertical Channel
Authors: Sadiq Kashif , Siddique Imran , Ali Rifaqat , Jarad Fahd
Published: October 2021

The mass and heat transport of Casson nanofluid flow in a channel under the influence of the magnetic field, heat generation, chemical reaction, ramped concentration, and ramped temperature is studied. Nanoparticles of copper (Cu) are inserted in sodium alginate (SA) to make nanofluid. The definition of time-fractional Caputo derivative is applied to have the fractional model. The analytical results of concentration, temperature, velocity, skin friction, Sherwood numbers, and Nusselt numbers for ramped and isothermal boundary conditions are obtained in the form of summation after applying the Laplace inverse transform. The effects of the fractional parameter (

ξ

) and physical parameters are depicted graphically. For higher values of

ξ

the velocity, concentration and temperature reduce. The fractional model is a better choice to control velocity, concentration, and temperature profiles. The energy enhances by increasing volume fraction (

ϕ

), whereas mass and flow of nanofluid reduce. The Sherwood and Nusselt numbers for both isothermal and ramped conditions increase by increasing

ϕ

. Ramped conditions can control the flow, mass, and heat of the nanofluid.
Passive Wireless Sensor Network‐Based In‐Transit Health Status Monitoring for Railway Transportation
Authors: Wei Jianpeng , Song Yaduo
Published: October 2021

In this paper, passive wireless sensor network technology is used to conduct in‐depth research and analysis on the monitoring of the in‐transit health status of railway transportation. Safety detection sensors, train communication networks, and other onboard devices organically constitute a train sensor network with comprehensive state sensing, information aggregation, and business collaboration. First, this paper analyzes the three‐layer architecture of the sensing layer, network layer, and application layer of the train operation status safety detection sensor network. Based on analyzing the feasibility of Ethernet application in an onboard communication network, ring, multiring, and ladder‐type sensor network structure schemes are designed. Next, the real‐time performance and reliability of various sensor network structures are analyzed. First, the characteristics of bandwidth demand, priority, and importance of information transmission of each monitoring object are analyzed; then, the system utility function is established according to the bandwidth usage efficiency and communication demand of information transmission of each monitoring object; finally, the bandwidth allocation optimization model is solved by using a particle swarm optimization algorithm, and the remaining bandwidth resources are dynamically rationed on demand while ensuring the complete transmission of basic information of each monitoring object. Rail transit technology has profoundly affected and changed the travel and lifestyle of residents in the new era and will provide strong infrastructure support for the smooth advancement of new urbanization construction and development strategies. The remaining bandwidth resources are dynamically allocated on the premise of ensuring the complete transmission of basic information of each monitoring object. In summary, this paper presents a complete study on the optimal allocation of resources for wireless sensor networks dedicated to rail transit condition monitoring, starting from the perspectives of routing protocol optimization, data fusion rate optimization, and bandwidth dynamic allocation optimization to achieve the efficient use of limited resources. The achieved research results enrich the research content in the field of wireless monitoring of rail transit system conditions at home and abroad in a certain sense and will also provide theoretical and empirical support for practical practitioners, managers, and scholars of service condition monitoring of rail transit systems.