bluuebunny/crossref_metadata_2025 huggingface dataset:
[Retracted] Application of Multiple Regression Analysis Model in Table Tennis Competition
Authors: Li Yuanjing , Wang Yi , Gu Nan , Cao Yecheng , Ye Minghui
Published: August 2022

Since the table tennis mixed doubles competition was officially listed as the Olympic Games, the players around the world paid more attention to the project. In this background, the 20 mixed doubles finals were used in the literature, video observation, and analysis of multiple regression. From the receiving point of view, the score difference between men and women is not very great, but female players may be more consistent. The contribution of male and female scores to the game is more effective than model 1 and model 2 for different rounds. Therefore, model 2 is more efficient in the analysis of high‐level table tennis competitions. Multiple regression model can be used to analyze and predict table tennis singles, doubles, and mixed doubles games, which we will see more and more in future research results.
Artificial Intelligence Search and Language Landscape Translation Optimization under 5G Network
Authors: Wang Lun
Published: August 2022

In the process of building a city, the content of the language landscape directly reflects the level of development and civilization of the city. The language landscape of each city will change with the changes in humanities and local characteristics, so the translation of the language landscape is very important. This article analyzes the language landscape of a city in detail, introduces the meaning of the language landscape in detail, and also corrects the errors in the city’s language landscape translation process, and introduces people to the language landscape. In today’s social development process, the fifth-generation communication technology has gradually developed and matured, bringing more convenience to people’s daily lives. However, the upgraded communication technology still faces the problem of processing a large amount of data, and the traditional network system may not be able to bear the current data processing pressure. The emergence of artificial intelligence technology has created opportunities for the upgrading and development of communication technology. It can process a variety of complex data information at the same time and provide help for the smooth operation of the network system. The use of this communication network can also solve the deployment problem of network nodes and improve the efficiency and quality of language landscape translation to a certain extent.
Identifying RBBP7 as a Promising Diagnostic Biomarker for BK Virus-Associated Nephropathy
Authors: Wang Yicun , Wang Yuxuan , Zhang Di , Zhang Hao , Wang Wei , Hu Xiaopeng
Published: August 2022

BK virus-associated nephropathy (BKVN) remains a major infectious complication due to powerful immunosuppression in kidney transplant recipients, and its histologic appearance can mimic rejection, leading to diagnostic and treatment dilemmas thus molecular diagnostic methods would be beneficial. We collected gene expression profiles of 169 kidney biopsies taken from BKVN, rejection, and stable functioning allografts, based on single sample gene set enrichment analysis and random forest algorithm, and three hallmark activities associated with DNA damage and proliferation were found to be relatively specific in BKVN. Subsequently, weighted gene co-expression network analysis and support vector machines (SVM) algorithm identified RBBP7 as a robust and promising biomarker with high accuracy in both training and validation cohorts (AUC =0.938, 0.977, respectively). Besides, potential drugs for BKVN treatment such as mepacrine were discovered, which may contribute to targeted antiviral therapy and effective patient management rather than simply reducing the doses of immunosuppressive agents in clinical practice. RBBP7 (retinoblastoma binding protein 7) serves as component of serval complexes that regulate chromatin metabolism and functions in affecting DNA replication and controlling cell proliferation. In this research, upregulation of RBBP7 was found to be associated with the higher infiltration of CD8 naïve T, iTreg, and neutrophil cells and the lower amounts of Th1, central memory T, NKT, CD8 T, and dendritic cells. Moreover, the infiltration of Th1, Th17, and NKT cells was steadily different between BKVN and rejection allografts through immune cell assessment. In conclusion, we identified and verified RBBP7 as a molecular biomarker for BKVN diagnosis, which demonstrated great distinguishing ability with allograft rejection and would support clinical decision-making.
Coordinated Development of Smart City and Regional Industrial Economy under the Background of Internet of Things
Authors: Chen Liping
Published: August 2022

The development of wireless communication and the Internet of Things has promoted the construction of smart cities and is the technical basis for the construction of smart cities. The influence of regional economic development level on smart city construction cannot be ignored, and it constitutes the external environment of smart city construction. The combination of the two will play a driving role in the construction of smart cities. Therefore, the planning and construction of smart cities must be coordinated with the realization of the two. This paper adopts a combination of literature analysis and field investigation to analyze the decoupling between smart city construction and regional economic development, conduct research on relevant cities, and combine the current situation of smart city construction to collect the problems encountered in smart city construction and regional economic development. Through analysis, it provides suggestions for the development of smart cities and regional economic development. The survey results show that in the process of smart city construction and regional industrial economic development in the context of the Internet of Things, information security and lack of talent are the most prominent problems. Among the relevant suggestions on these issues, the proportion of talent introduction is about 45%, and the proportion of rational planning of industrial structure is about 28%. Based on the experience of existing research results, this study uses optimization algorithms to make the impact of various factors more specific, which is helpful for each region to make scientific planning based on its own actual situation.
Weighted Joint Sentiment-Topic Model for Sentiment Analysis Compared to ALGA: Adaptive Lexicon Learning Using Genetic Algorithm
Authors: Osmani Amjad , Bagherzadeh Mohasefi Jamshid
Published: August 2022

Latent Dirichlet Allocation (LDA) is an approach to unsupervised learning that aims to investigate the semantics among words in a document as well as the influence of a subject on a word. As an LDA-based model, Joint Sentiment-Topic (JST) examines the impact of topics and emotions on words. The emotion parameter is insufficient, and additional parameters may play valuable roles in achieving better performance. In this study, two new topic models, Weighted Joint Sentiment-Topic (WJST) and Weighted Joint Sentiment-Topic 1 (WJST1), have been presented to extend and improve JST through two new parameters that can generate a sentiment dictionary. In the proposed methods, each word in a document affects its neighbors, and different words in the document may be affected simultaneously by several neighbor words. Therefore, proposed models consider the effect of words on each other, which, from our view, is an important factor and can increase the performance of baseline methods. Regarding evaluation results, the new parameters have an immense effect on model accuracy. While not requiring labeled data, the proposed methods are more accurate than discriminative models such as SVM and logistic regression in accordance with evaluation results. The proposed methods are simple with a low number of parameters. While providing a broad perception of connections between different words in documents of a single collection (single-domain) or multiple collections (multidomain), the proposed methods have prepared solutions for two different situations (single-domain and multidomain). WJST is suitable for multidomain datasets, and WJST1 is a version of WJST which is suitable for single-domain datasets. While being able to detect emotion at the level of the document, the proposed models improve the evaluation outcomes of the baseline approaches. Thirteen datasets with different sizes have been used in implementations. In this study, perplexity, opinion mining at the level of the document, and topic_coherency are employed for assessment. Also, a statistical test called Friedman test is used to check whether the results of the proposed models are statistically different from the results of other algorithms. As can be seen from results, the accuracy of proposed methods is above 80% for most of the datasets. WJST1 achieves the highest accuracy on Movie dataset with 97 percent, and WJST achieves the highest accuracy on Electronic dataset with 86 percent. The proposed models obtain better results compared to Adaptive Lexicon learning using Genetic Algorithm (ALGA), which employs an evolutionary approach to make an emotion dictionary. Results show that the proposed methods perform better with different topic number settings, especially for WJST1 with 97% accuracy at |Z| = 5 on the Movie dataset.
Precise Asymptotics for the Uniform Empirical Process and the Uniform Sample Quantile Process
Authors: Chen Youyou , Qian Zaichen
Published: August 2022

One of the sources of “invariance principle” is that the limit properties of the uniform empirical process coincide with that of a Brownian bridge. The deep discussion of limit theorem of the uniform empirical process gathered wild interest of the researchers. In this paper, the precise convergence rate of the uniform empirical process is considered. As is well-known, when

ε

tends to 0, the precise asymptotic theorems can be demonstrated by referring to the classical method of Gut and Spǎtaru, by using some nice probability inequalities and so on. However, if

ε

tends to a positive constant, other powerful methods and tools are needed. The method of strong approximation is used in this paper. The main theorems are proved by using the Brownian bridge

B

t

to approximate the uniform empirical process

α

n

t

. The relevant results for the uniform sample quantile process are also presented.
The Protection of Architectural Heritage in the Process of Urbanization under the Internet Environment
Authors: Zhang Yin , He Lu , Tu Zhongfang
Published: August 2022

The urbanization process is speeding up in the Internet age, and many architectural heritages will be harmed as a result. This paper examines the coupling relationship between architectural heritage protection and tourism development using the concepts of architectural heritage protection and tourism development, as well as coupling theory. A preliminary analysis of the mechanism of the coupling relationship between architectural heritage protection and tourism development is conducted. Under unsupervised conditions, the classification results and quantitative index classification results of architectural heritage are obtained using the cluster analysis method. The sigs of historical, artistic, scientific, and humanistic factors, according to variance analysis, are 0.003, 0.041, 0.011, and 0.013, respectively, all of which are less than 0.05, with a significant difference. The spatial factor variable has a sig value of 0.52, which is not significant. This method can be used to not only classify heritage but also to quantify architectural heritage factors. In the future work of cultural relics protection, we can broaden the scope of protection measures and make recommendations to protection workers.
The Effects of Statin Therapy on Oxidized LDL and Its Antibodies: A Systematic Review and Meta-Analysis
Authors: Jamialahmadi Tannaz , Baratzadeh Fatemeh , Reiner Željko , Mannarino Massimo R. , Cardenia Vladimiro , Simental-Mendía Luis E. , Pirro Matteo , Watts Gerald F. , Sahebkar Amirhossein
Published: August 2022

Background. Elevated serum low-density lipoproteins (LDL), the substrate for the formation of atherogenic oxidized LDLs (oxLDL), are a causal factor for atherosclerotic cardiovascular disease (ASCVD). Statins are well known to decrease LDL particle concentration and reduce ASCVD morbidity and mortality. Objective. To perform a meta-analysis of the effects of statins (i.e., type, dose, and duration of treatment) on serum levels of oxLDL and on immunoglobulin M (IgM) and immunoglobulin G (IgG) antibody levels against oxLDL. Methods. PubMed, Scopus, Embase, and Web of Science were searched up to February 5th, 2021, for randomized controlled trials (RCT) evaluating the effect of statins on oxLDL and anti-oxLDL antibody levels. Meta-analysis was performed using Comprehensive Meta-Analysis (CMA) V2 software. To evaluate the influence of each study on the overall effect size, a sensitivity analysis was performed using the leave-one-out method. Evaluation of the funnel plot, Begg’s rank correlation, and Egger’s weighted regression tests was used to assess the presence of publication bias in the meta-analysis. Results. A total of 28 RCTs including 4019 subjects were finally included in the meta-analysis. The results indicated a significant decrease in circulating concentrations of oxLDL after treatment with statins (SMD: -2.150, 95% CI: -2.640, -1.697,

p
<
0.001

). Subgroup analysis found no significant effect of the intensity of statin treatment or statin lipophilicity on the reduction of circulating concentrations of oxLDL. An additional meta-analysis of 3 trials showed that statins did not change the serum levels of IgM and IgG antibodies to oxLDL. Conclusion. Statin therapy decreases serum oxLDL concentrations but does not affect circulating levels of anti-oxLDL antibodies.
Optimization Method of High-Speed Train Composite Material Workshop Planning and Scheduling
Authors: Jie Yanliang , Hao Lei , Yan Shujun , Zhang Xueli
Published: August 2022

With the continuous speed increase of high-speed trains, higher performance requirements are put forward for the braking technology and braking device. In order to improve productivity and overall competitiveness, manufacturing companies are actively researching new manufacturing technologies and production methods, and shop floor scheduling is one of the core components of this problem. This paper mainly studies the high-speed train composite workshop planning and scheduling optimization method. This experiment adopts B/S-based architecture mode. The prototype system is developed with Microsoft’s integrated development platform Visual Studio 2013, and Microsoft’s SQL Server 2008 is used as the background database management system. The experiment mainly uses the white box test method; the test content mainly includes module interface test, module local data structure test, and module boundary test. The interface parameters of each module are checked, and the boundary values of some functions are also analyzed and tested. According to the results, the planning management personnel revise the priority order again until all the molds meet the requirements of delivery and constraints. If the scheduled results do not meet the requirements, the methods such as those compressing the lead time, those urging the casting to be in place in advance, single process outsourcing, and overtime shall be considered. In this paper, a layered coding strategy is adopted. The first layer of coding represents the batch processing sequence. The second layer of coding determines to which process the corresponding batch belongs to. Each layer of coding is divided into different machine segments to represent the batch processing sequence on different machines. When the production process needs to switch orders, it can know which equipment parameters need to be adjusted in advance, which can effectively avoid the wrong operation caused by temporary adjustment of production parameters, reduce the order switching time, and improve the utilization rate of the production line. The data show that, compared with the artificial experience method and the priority rule method, the order production cycle after genetic optimization is reduced by 7.34% and 8.98%, respectively. The results show that the workshop scheduling optimization can help enterprises save stamping scheduling time, reduce production costs, and improve the rationality of scheduling.
Design of an Automobile Injection Mould Based on Automation Technology
Authors: Cao Silin , Si Guimao
Published: August 2022

At present, there are frequent occurrences in the industry of manufacturers only having products, but they have no product data, resulting in manufacturers unable to open molds to produce the products themselves and can only buy them at high prices. This article takes the rear case of an automobile generator produced by a company as an example, which aims to show the design of automobile injection molds through automation technology. This paper studies the use of automation technology to achieve the automatic model reconstruction of products, and uses the CAD technology to design injection molds based on the obtained digital models of products. This paper also uses the CAE technology to verify the feasibility and rationality of the designed mold, exploring the optimization method of the injection molding process of the mold. In this paper, a special product pouring system and demolding mechanism are designed according to the product process requirements. The design greatly simplifies the mold structure while fulfilling the product process requirements, which avoids the use of expensive hot runners and complex flip-chip mold structures, reducing the mold manufacturing cost. Secondly, the overall design of the injection mold is carried out, and the external dimensions and other main parameters of the mold are determined. Then, Moldflow software is used to simulate the injection molding process, verifying the feasibility and rationality of the designed mold. The optimization method of the injection molding process is also proposed, and the optimal injection process parameters are determined to ensure that the mold can produce qualified products and ensure high production efficiency. It can be seen from the analysis results that the maximum warpage deformation of the plastic part under all effects is 0.65 mm, which meets the product process requirements.
The Evaluation Method of Community Emergency Resource Allocation Based on Coordination Sensor Information Collection
Authors: Wang Peixian , Wang Fuguang , Zhu Zhu
Published: August 2022

This paper analyzes the information collection data of coordination sensors and designs a corresponding evaluation method to conduct an in-depth assessment of the configuration of community emergency resources. Based on the principles of assessment index system construction and the actual research, an assessment index system of community emergency resource allocation level is established. In this paper, the G1 method was selected to determine the weights of the evaluation indexes, and the gray clustering method was applied to construct the whitening weight function, determine the gray level to which each index belongs and the affiliation degree of each gray class, and establish a comprehensive evaluation model of the community emergency resource allocation level. In response to the problem that the increase of state variables leads to a decrease in real-time map building, a dynamic local window size mechanism is proposed, which can reduce the time consumption and save computational resources under the condition of ensuring the accuracy of positioning and map building. Therefore, it is urgent to design an efficient self-interference cancellation mechanism to resist the influence of self-interference on the signal-to-noise ratio of the first-hop link. For example, the IMU pre integration theory is combined with the wheel range method to solve the problem of frequency synchronization; An initialization algorithm is proposed to recover the scale information of the camera and optimize the external parameters; Design a graphic optimization framework integrating IMU, wheel range finder and camera. The monitoring terminal sends the data information of coordination transportation to the monitoring platform in real-time, and the monitoring platform is responsible for storing and displaying the data information, thus realizing the real-time monitoring of the coordination transportation process. Finally, the functions of the monitoring terminal and the display system of the monitoring platform experiment, respectively, and the test results verify the effectiveness and integrity of the system data communication, which proves the correctness of the terminal design of the integrated coordination monitoring system based on multidimensional information and has practical engineering value.
[Retracted] To Investigate Whether Hematocrit Affects Thromboelastography Parameters
Authors: Zhang Min , He Keyu , Ye Dong , Zhang Qiang , Zhang Zhengkang
Published: August 2022

Background. Thromboelastogram (TEG) is an experiment to detect coagulation function with whole blood. Red blood cell (RBC) is the most abundant component of blood. Whether RBC has an impact on the results of thromboelastogram? Study Design and Methods. The correlation between hematocrit (HCT) and TEG was analyzed. 17 samples were reconstituted with different HCT. They were tested separately. Correction tests were performed on 17 samples from patients with anemia. HCT was corrected to 0.40 in female and 0.45 in males. The correction formula was determined according to the experimental correction. Results. HCT was negatively correlated with TEG parameters. As HCT increased, CI and angle decreased (P < 0.05, P < 0.001) and K increased (P < 0.001) in reconstituted samples. In the correction test, the angle measured value was 69.48 ± 4.98 and corrected value was 62.48 ± 6.25, MA measured value was 61.44 ± 7.10 and corrected value was 55.94 ± 7.12, K measured value was 1.45 ± 0.48 and corrected value was 2.11 ± 0.79, and CI measured value was 1.07 ± 1.67 and corrected value was −0.45 ± 1.64. There was a significant difference. The correction formulas of anemia were derived from the experimental correction results. KCorrection value = (0.7903∗A2 − 2.1803A + 2.8268)∗KMeasured value; Tan angleCorrection value = Tan angleMeasured value/(0.6596∗A2 − 1.7478A + 2.4608); MACorrection value = MAMeasured value/(0.1853ln (A) + 1.0197); CICorrection value = −0.6516RMeasured value − 0.3772KCorrection value + 0.1224MACorrection value + 0.0759angleCorrection value − 7.7922. Conclusion. HCT has a negative impact on TEG parameters. Coagulation state of anemia patients is overestimated by TEG. The test results of anemia patients need to be corrected whether through the experimental correction or the formula correction.
Characterizations and Properties of Monic Principal Skew Codes over Rings
Authors: Boulagouaz Mhammed , Deajim Abdulaziz
Published: August 2022

Let

A

be a ring with identity,

σ

a ring endomorphism of

A

that maps the identity to itself,

δ

a

σ

-derivation of

A

, and consider the skew-polynomial ring

A

X
;
σ
,
δ

. When

A

is a finite field, a Galois ring, or a general ring, some fairly recent literature used

A

X
;
σ
,
δ

to construct new interesting codes (e.g., skew-cyclic and skew-constacyclic codes) that generalize their classical counterparts over finite fields (e.g., cyclic and constacyclic linear codes). This paper presents results concerning monic principal skew codes, called herein monic principal

f
,
σ
,
δ

-codes, where

f
∈
A

X
;
σ
,
δ

is monic. We provide recursive formulas that compute the entries of both a generator matrix and a control matrix of such a code

C

. When

A

is a finite commutative ring and

σ

is a ring automorphism of

A

, we also give recursive formulas for the entries of a parity-check matrix of

C

. Also, in this case, with

δ
=
0

, we present a characterization of monic principal

σ

-codes whose dual codes are also monic principal

σ

-codes, and we deduce a characterization of self-dual monic principal

σ

-codes. Some corollaries concerning monic principal

σ

-constacyclic codes are also given, and a good number of highlighting examples is provided.
A Dual-Position Loop LLADRC Control Method Based on Harmonic Gear Drive
Authors: Cao Yu , Wang Fan , Li Xin , Su Xiuqin , Guo Shan , Han Junfeng , Xie Meilin , Wang Lei , Feng Xubin
Published: August 2022

High-resolution imaging has become a development trend and is widely used in military and civil fields. As the carrying equipment of imaging system, the speed stability of tracking turntable is the basis of high-resolution and stable imaging. At present, in the aerospace field, there are high requirements for peak power dissipation and holding torque, so flexible joints such as harmonic gear drive are mostly used to realize the function. The characteristics of flexible load have a great impact on the characteristics of motion control, which is easy to cause mechanical resonance, lead to system instability, and have a great impact on speed stability and position tracking accuracy. Therefore, it is necessary to study the servo system of flexible load. In order to solve the problems of high-precision position control and speed stability at low speed of flexible turntable with uncertain load, on the one hand, we comprehensively consider the advantages and disadvantages of semi-closed-loop and full closed-loop control and design a dual-position loop feedback control system combined with the analysis of dynamic equation to realize speed stability and high-precision position control. On the other hand, according to the requirements of the speed stability at low speed of the turntable, the tracking differentiator (TD) is designed innovatively through the language three-point interpolation subdivision and five-point pre-deduction calculation method. Finally, a dual-position loop LLADRC (language linear active disturbances rejection controller) control method based on harmonic gear drive is studied. By comparing the semi-closed loop, dual-position loop, dual-position loop LADRC (linear active disturbances rejection controller, ADRC), and dual-position loop LLADRC methods through simulation analysis, it can be shown that the double position LLADRC control method is obviously superior to other schemes in terms of rapidity, speed stability at low speed, and position tracking accuracy. The theoretical research is verified by experimental test. When the given speed is

0.1

°

/
s

, taking the pitch axis as an example, the pitch speed error is

0.0039

°

/
s

(3σ). When the maximum speed of the given curve is

20

°

/
s

and the maximum acceleration is

16

°

/
s

, the position tracking error is 0.0025° (3σ). This control method solves the problems of system instability and low-speed stability in high-precision control of turntable system based on harmonic gear drive and provides a method for high-precision control of high-resolution imaging turntable.
Study on Cooperative Multipoint Communication Precoding Algorithm under SLNR-MMSE Framework
Authors: Fan Yu
Published: August 2022

With the rapid growth of demand for wireless data services and the continuous introduction of new air interface technologies, mobile communication systems continue to face new challenges in supporting high-speed multimedia service transmission and achieving seamless coverage. In order to meet the requirements of the IMS system in terms of bandwidth, peak rate, communication throughput, etc., multiantenna enhancement technology and cooperative multipoint transmission technology have become research hotspots as key technologies. In the study of multiuser system, this paper focuses on the precoding technology based on noncode book, based on the minimum mean square error criterion and the maximum letter leakage noise ratio criterion, studies the precoding technology of different multiuser systems, expounds the collaborative multipoint transmission system, and makes a basic classification. The signal leakage-to-noise ratio precoding algorithm and the minimum mean square error precoding algorithm are analyzed in detail. In view of the shortcomings of these two algorithms, this paper takes the minimum sum of the total mean square error of the system as the optimization goal of the combinations of precoding and power allocation. The precoding algorithm of SLNR-MMSE is proposed. The simulation analysis shows that the proposed algorithm has certain advantages over other algorithms in terms of bit error rate and system capacity. It shows that this study is important for optimizing collaborative multipoint communication system.
Challenges and perspectives of the use of photovoltaic solar energy in Colombia
Authors: Moreno Rocha Christian Manuel , Milanés Batista Celene , Arguello Rodríguez Willian Fernando , Fontalvo Ballesteros Arley Jesús , Núñez Álvarez José Ricardo
Published: August 2022

This article quantifies the development of photovoltaic solar energy in Colombia and its current development prospects. The high demand for electricity in Colombia is increasing since there is a large population, industrial, and business increase, which brings a higher energy consumption and consequently economic, social, and environmental problems. Faced with this situation, a possible solution is proposed, using solar energy, to supply the increase in demand and mitigate the problems caused by current electricity generation because Colombia has high levels of solar radiation in almost the entire territory. The objective of this research is based on the analysis of the behavior of the projects on photovoltaic solar systems presented to the mining-energy planning unit (UPME) in the last 14 years until September 30, 2020, as well such as the study of the areas with the most effective implementation of this technology and their respective radiation indices. In addition, a synthesis is made of the regulations, laws, and tax incentives that exist for the implementation of this technology and the different stages of execution of the projects approved and in performance.
Extraction of photovoltaic generator parameters through combination of an analytical and iterative approach
Authors: Benahmida Abdelaaziz , Maouhoub Noureddine , Tifidat Kawtar , Sahsah Hassan
Published: August 2022

In the present work, we propose an improved method based on a combination of an analytical and iterative approach to extract the photovoltaic (PV) module parameters using the measured current-voltage characteristics and the simple diode model. First, we calculate the series resistance using a set of analytical formulas for the base values of the three current-voltage curves. Then, the three other parameters are analytically expressed as functions of serial resistance and ideality factor based on the linear least-squares method. Finally, the ideality factor is calculated applying an iterative algorithm to minimize the normalized root mean square error (NRMSE) value. The proposed method was validated with a real experimental set of two PV generators, which showed the best fit to the I-V curve. Moreover, the proposed method needs only the initial value of the ideality factor.
Optimization of fuzzy photovoltaic maximum power point tracking controller using chimp algorithm
Authors: Al-Gizi Ammar , Hussien Miry Abbas , A. Shehab Mohanad
Published: August 2022

In this paper, a photovoltaic (PV) fuzzy maximum power point tracking (MPPT) method optimized by the chimp algorithm is presented. The fuzzy logic controller (FLC) of seven triangular membership functions (MFs) is used. The optimization fitness function is composed of transient and steady-state indices under different irradiation and temperature operating conditions. By using MATLAB package, the performance of optimized method is examined and compared with asymmetrical FLC and well-known perturb and observe (P&O) tracking methods at different operating conditions in terms of: transient rising time (tr) and energy yield during 30 s. Moreover, the tracking methods are also compared in terms of the fitness function value. From the comparison of simulation results, a more energy can be harvested by using the proposed optimized tracking method compared to the other methods. Consequently, at the various operating conditions, the proposed method can be used as a more reliable tracking method for PV systems.
Parameter estimation and control design of solar maximum power point tracking
Authors: Hasan Mashhood , Alhazmi Waleed Hassan , Zakri Waleed , Khan Anwar Ulla
Published: August 2022

Parameters evaluation, design, and intelligent control of the solar photovoltaic model are presented in this work. The parameters of zeta converters such as a rating of an inductor, capacitor, and switches for a particular load are evaluated its values to compare the trade of the existing model and promoted to research in the proposed area. The zeta converter is pulsed through intelligent controller-based maximum power point tracking (intelligent-MPPT). The intelligent controller is a fuzzy logic controller (FLC) which extracts maximum power from the solar panel using the zeta converter. The performance of evaluated parameters based on the solar system and zeta converter is seen by an intelligent control algorithm. Moreover, evaluated parameters of solar photovoltaic (PV) and zeta converter can be examined the performance of fuzzy based intelligent MPPT under transient and steady-state conditions with different solar insolation. The brushless direct current motor-based water pump is used as the direct control (DC) load of the proposed model. The proposed model can enhance the research and assist to develop a new configuration of the present system.
Wind energy integration in Africa: development, impacts and barriers
Authors: Haidi Touria , Cheddadi Bouchra
Published: August 2022

The African renewable energy initiative (AREI), adopted in 2015 by nearly half of the African countries, planned to install 10 GW of renewable energy by the end of 2020 and 300 GW by 2030, of which 100 GW would be wind. These countries have each adopted their own national energy strategy defining their rate of renewable electricity capacity, particularly wind, in the overall energy mix by 2020 and/or 2030. This article aims to assess the implementation of these strategies by evaluating the up-to-date achievements in regards to wind energy and thus infer the AREI realization rate by the end of 2020. It focuses on the wind energy investments of the major African countries while comparing their effective realization rates with those targeted by their national strategies. This article also covers the impact of wind energy integration and the barriers to its development in Africa. Taking into account the recent study published in 2020 by the Global Wind Energy Council which assessed the wind energy potential in Africa at 59 TW, the obtained results show that the huge wind power potential in Africa is still far from being exploited and that only Morocco, Egypt and South Africa are on the right track.
Impacts of integration of wind farms on voltage stability margin
Authors: Attar Hani , Kamarposhti Mehrdad Ahmadi , Ahmed Solyman Ahmed Amin
Published: August 2022

The current methods use conservative voltage based on the maximum wind speed with simultaneous occurrence in peak loading conditions to determine the maximum size of the wind farm. Wind patterns never let the wind farm on the wind farm site produce its maximum capacity during hours of heavy loading conditions. A new method is presented in this research to determine the maximum size of wind farms including voltage stability margin (VSM) and wind patterns at the wind farm site in the size of a wind farm. This plan is a method to increase the maximum size of a wind farm with a limited wind generation option under certain conditions based on VSM. The proposed method is applied to the wind farm in the IEEE 14-bus network power system. The results of the new method show that the maximum size of wind farms increases when the system operates with intermittent wind control to maintain the voltage stability.
Electromagnetic interference measurement for axle counters light rapid transit railway in Indonesia
Authors: Yudhistira Yudhistira , Yoppy Yoppy , Trivida Elvina , Wahyu Wijanarko Tyas Ari , Nugroho Hutomo Wahyu , Mandaris Dwi
Published: August 2022

The measurement and analysis of electromagnetic interference (EMI) from light rapid transit (LRT) axle counters against magnetic field interference in Indonesia has been carried out. The low-cost magnetic sensors were developed according to the British Standard (BS) EN 50592:2016. The measurement setup and magnetic field limit were based on the British Standard EN 50592:2016 and ERA/ERTMS/033281 standard. Two frequency range of the measurements, lower and higher frequencies with two different train running mode, acceleration mode and deceleration mode were applied in this research. The results in lower frequency range (10 to 100 kHz) were very close to the limit value in both acceleration and deceleration mode, especially at the 30 to 50 kHz for the y and z directions. Although there may possibly magnetic interference at low frequencies, most of the magnetic field emissions were still in acceptable range.
MATLAB/Simulink modeling of electric motors operating with harmonics and unbalance
Authors: Bolaño Martínez Adrián , Jimenez Navarro Isaac , Sousa Santos Vladimir , Quispe Enrique Ciro , Daniel Donolo Pablo
Published: August 2022

This paper aims to present a simulation model for the analysis of the operational characteristics of electric motors (EMs). The model was developed on the Simulink platform of the MATLAB program and allows analysis in supply conditions with harmonics and voltage unbalance. The contribution of the model is that it considers the mechanical losses and provides for the study of the effect of each component of the electrical sequence of the harmonics and the voltage unbalance on the electromechanical characteristics of the EM. The model developed was tested in a 37.3 kW EM, operating under four power supply conditions: balanced sinusoidal voltages, balanced non-sinusoidal voltages (i.e., harmonics), unbalanced sinusoidal voltages, and non-sinusoidal unbalanced voltages. The results showed that under the conditions of harmonics and unbalance, the efficiency was reduced by 2%, respectively and that with the combined effects, the efficiency decreased by 4%. The results made it possible to quantify, from the current, voltage, and electrical power values of each sequence, the adverse effects caused by voltage unbalance and harmonics.
Particle swarm optimization and Taguchi algorithm-based power system stabilizer-effect of light loading condition
Authors: Kalegowda Kumara , Iyengar Srinivasan Amruthur Doreswamy , Chinnamadha Nagaraj
Published: August 2022

A robust design of particle swarm optimization (PSO) and Taguchi algorithm-based power system stabilizer (PSS) is presented in this paper. It incorporates a novel concept in which Taguchi and PSO techniques are integrated for stabilization of single machine infinite bus (SMIB). The system tolerates uncertainty and imprecision to a maximum extent. The proposed controller's effectiveness is proved through experiments covering light load condition using MATLAB/Simulink platform. The performance of the system is compared without PSS and with a conventional PSS. The settling time of the optimal PSS is decreased by more than 75% to conventional PSS. The study reveals that the proposed hybrid controller offers enhanced performance with respect to settling time as well as peak overshoot of the system.
Optimized servo-speed control of wind turbine coupled to doubly fed induction generator
Authors: Mansouri Abdelhamid , Krim Fateh
Published: August 2022

Optimal control of any variable speed wind turbine needs maximum power point tracking (MPPT) coupled to doubly fed induction generator (DFIG) for better power generation. This paper offers a novel direct power servo-speed control of wind turbine. This latter is based on DFIG optimal hysteresis MPPT inverter current control combined with space voltage modulation (SVM) inverter voltage technique, thus providing a stable and continuous energy flow to power grid. In this design, the asynchronous machine stator is directly connected to the grid. Bidirectional power converter, acting as frequency converter, is rotor circuit located. Rectifier supplies rotor windings with voltages and reference frequency resulting from control procedure of the power exchange between the stator and grid. Inverter is directly controlled by means of SVM technique to maintain direct current (DC) bus voltage constant. Simulation results show that the proposed configuration improves power converters efficiency due that rotor circuit needs less power than stator circuit which is injected into the grid.
Computer-aided diagnostic system kinds and pulmonary nodule detection efficacy
Authors: Kadhim Omar Raad , Motlak Hassan Jassim , Abdalla Kasim Karam
Published: August 2022

This paper summarizes the literature on computer-aided detection (CAD) systems used to identify and diagnose lung nodules in images obtained with computed tomography (CT) scanners. The importance of developing such systems lies in the fact that the process of manually detecting lung nodules is painstaking and sequential work for radiologists, as it takes a long time. Moreover, the pulmonary nodules have multiple appearances and shapes, and the large number of slices generated by the scanner creates great difficulty in accurately locating the lung nodules. The handcraft nodules detection process can be caused by messing some nodules spicily when these nodules' diameter be less than 10 mm. So, the CAD system is an essential assistant to the radiologist in this case of nodule detection, and it contributed to reducing time consumption in nodules detection; moreover, it applied more accuracy in this field. The objective of this paper is to follow up on current and previous work on lung cancer detection and lung nodule diagnosis. This literature dealt with a group of specialized systems in this field quickly and showed the methods used in them. It dealt with an emphasis on a system based on deep learning involving neural convolution networks.
Application of green-emitting ZnS:Eu2+ for boosting the spectrum of white light-emitting diode packages
Authors: Nguyen Thi Dieu An , Dang Huu Phuc
Published: August 2022

Through utilizing a nonlinear application to acquire the best lumen efficiency (LE) for radiation (also known as LER) when color rendering index (CRI) value, especially CRI of R9 for strong red exceeds 90 with correlated color temperature (CCT) range of 2700-6500 K, the white light emitting diodes (WLED) package with adjustable CCT value and comprised of mixed-type light-emitting diodes (LEDs) can be acquired. The WLED model here contains blue and red LEDs with direct emission and a phosphorconversion blue LED or pc/B-LED (including orange and green phosphors mixed with blue LED colorant). The peak wavelengths of each LED constituent are 465 and 628 nm for LEDs in blue and red, 452 nm for the blue LED colorant, 530 and 586 nm for the phosphors exhibiting green and orange colors. Under the CCT of 2722-6464 K, the attained actual LED package, either with conversion phosphor, in red or in blue, possibly displays both CRI and R9 values measured from 90 to 96, color quality scale (CQS) values measured from 89 to 94, with LERs and LEs of 303-358 lm/W and 105-119 lm/W, respectively.
An efficient optical inspection of photovoltaic modules deploying edge detectors and ancillary techniques
Authors: Raghavendra Kummara Venkata Guru , Kumar Nutakki Tirumala Uday , Kazim Waqarullah
Published: August 2022

With the enhanced industrial and domestic energy needs, there is a great urge for renewable energy sources because of their eco-friendly nature. Solar energy is crucial among renewable energy sources and there is a great need to optimize and enhance the performance of solar energy usage that is mainly dependent on the system components. The current work has been aimed to discuss the fault detection of photovoltaic (PV) modules by evaluating an efficient, facile inspection algorithm electrical analysis for real-time applications. The paper presents a real-time experimental model for infrared thermography using a thermal imager mounted on a tripod at a suitable distance from the PV modules to capture the images in the best possible way. A novel hybrid algorithm has been proposed and the fault detection along with the electrical parameter analysis has been accurately performed on the PV modules to analyze and process various externally induced faults in the PV systems.
Real time hardware implementation of discrete sliding mode fuzzy controlled buck converter using digital signal processor
Authors: Karthikeyan Viji , Tiwari Anil Kumar , Kandasamy Chitra
Published: August 2022

This paper deals with the real time hardware implementation of discrete sliding mode fuzzy control (DSMFC) for buck converter using digital signal processor (DSP). Applications like electric vehicle suspension control, flight dynamic control, robot position control and engine throttle position control; sliding mode control (SMC) plays a major role. Hardware realization is difficult with SMC strategy due to the continuous gain change results in chattering problem and actuator or contact may break. To resolve this problem the fuzzy logic (FL) approach has combined with the robust technique discrete sliding mode control (DSMC) to develop a new strategy for DSMFC. The mathematical modeling of the controller is done using MATLAB/Simulink software and practical design of the converter is also realized. The robustness of the controller is proved by introducing sudden change in input voltage as well as load with the help of switching circuit in hardware realization. The obtained practical results are verified by comparing with the simulation output and reference value.
Multi-phase inverter-controlled induction machine at varied rotor parameters
Authors: Omeje Crescent Onyebuchi , Nnadi Damian Benneth , Oti Stephen Ejiofor
Published: August 2022

This paper presents a step-wise modelling of a symmetrical six-phase induction machine driven by a six-phase diode clamped multi-level inverter at a varying rotor resistance and motor inertia. The machine drive process was considered in two stages. The first stage presents the dynamic behavior of the machine when a load torque of 0 Nm and 100 Nm is applied at a varied rotor external resistance value of (0.8 and 3.2) Ω with constant motor inertia. The second stage showcased the variations in the speed, electromagnetic torque and rotor current when motor inertia is varied at (0.5 and 1.5) Kg-m2 with rotor resistance held constant. A six-phase five-level diode clamped converter phase displaced by sixty degrees with a modulation index of 0.8 was modeled to drive the poly-phase machine at a reduced %THD. All machine models were simulated in MATLAB 7.11. The simulation results showed that reduced oscillations in rotor current, motor speed and torque pulsations were achieved at a varied external rotor resistance and motor inertia.
In-wheel, outer rotor, permanent magnet synchronous motor design with improved torque density for electric vehicle applications
Authors: Bdewi Mustafa Yaseen , Ezzaldean Ali Mohammed Moanes , Mohammed Ahmed Mahmood
Published: August 2022

In electric vehicle applications, the torque density of electric motor plays an important role in improving the performance of the vehicle. The main objective of this paper is to investigate a possible method for improving the torque density of a permanent magnet synchronous motor used in electric vehicles. At the same time, other machine specifications were taken into account and kept within the acceptable level. This was achieved by incorporating performance enhancement strategies such as investigating ofhigh-efficient winding topology for the motor’s stator to give the highest winding factor and optimizing the machine dimensions to achieve the best performance. MagNet 7.4.1 software package with static and transient finite element method solver was used for implementing the proposed design. The results showed a significant improvement in the torque density with keeping the overall machine performance.