165 results
Search Results
2. Analysis of Persian Bioinformatics Research with Topic Modeling.
- Author
-
Ebrahimi, Fezzeh, Dehghani, Mohammad, and Makkizadeh, Fatemah
- Subjects
LIFE sciences ,RESEARCH ,BIOMARKERS ,PHONOLOGICAL awareness ,MATHEMATICAL models ,NATURAL language processing ,RESEARCH methodology ,BIBLIOMETRICS ,MOLECULAR models ,BIOINFORMATICS ,MATHEMATICS ,CITATION analysis ,GENE expression ,THEORY ,MEDICAL research ,INFORMATION technology ,ALGORITHMS - Abstract
Purpose. As a scientific field, bioinformatics has drawn remarkable attention from various fields, such as information technology, mathematics, and modern biological sciences, in recent years. The topic models originating from the field of natural language processing have become the focus of attention with the rapid accumulation of biological datasets. Thus, this research is aimed at modeling the topic content of the bioinformatics literature presented by Iranian researchers in the Scopus Citation Database. Methodology. This research was a descriptive-exploratory study, and the studied population included 3899 papers indexed in the Scopus database, which had been indexed in this database until March 9, 2022. The topic modeling was then performed on the abstracts and titles of the papers. A combination of LDA and TF-IDF was utilized for topic modeling. Findings. The data analysis with topic modeling resulted in identifying seven main topics "Molecular Modeling," "Gene Expression," "Biomarker," "Coronavirus," "Immunoinformatics," "Cancer Bioinformatics," and "Systems Biology." Moreover, "Systems Biology" and "Coronavirus" had the largest and smallest clusters, respectively. Conclusion. The present investigation demonstrated an acceptable performance for the LDA algorithm in classifying the topics included in this field. The extracted topic clusters indicated excellent consistency and topic connection with each other. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
3. HWOA‐TTA: A New Hybrid Metaheuristic Algorithm for Global Optimization and Engineering Design Applications.
- Author
-
Najm, Huda Y., Khaleel, Elaf Sulaiman, Hamed, Eman T., Ahmed, Huda I., and Elgindy, Kareem T.
- Subjects
BENCHMARK testing (Engineering) ,ENGINEERING design ,MATHEMATICAL models ,ENGINEERING models ,METAHEURISTIC algorithms ,ALGORITHMS - Abstract
Hybrid metaheuristics is one of the most exciting improvements in optimization and metaheuristic algorithms. A current research topic combines two algorithms to provide a more advanced solution to optimization problems. The present study applies a new approach called HWOA‐TTA which means a hybrid of the whale optimizer algorithm (WOA) and tiki‐taka algorithm (TTA). The hybrid WOA‐TTA combines the exploitation phase of WOA with the exploration phase of TTA. Two stages in the hybridized model are suggested. First, the WOA exploitation phase incorporates the TTA mechanism. Second, a new approach is included in the research phase to enhance the result with each iteration to a set of unconstrained benchmark test functions and engineering design applications. To verify the performance of the improved algorithm, thirteen benchmark functions have been used to compare HWOA‐TTA with the classical intelligent population algorithms (PSO, TTA, and WOA). The hybrid algorithm is applied to two well‐known engineering mathematical models. The experiments show that the HWOA‐TTA outperforms other algorithms. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
4. Visual Analysis of Sports Actions Based on Machine Learning and Distributed Expectation Maximization Algorithm.
- Author
-
Luo, Yan
- Subjects
GREEDY algorithms ,ALGORITHMS ,MATHEMATICAL models ,MACHINE learning ,EXPECTATION-maximization algorithms ,SURFACE structure ,SPORTS - Abstract
In order to improve the scientificity of sports action analysis, this paper constructs a sports action analysis model based on machine learning based on the greedy algorithm and the bat algorithm. According to the structural characteristics of the model, the structure of the model is reflected in the form of face order, that is, the face neighborhood structure. Moreover, this paper judges the degree of similarity between model faces through the pros and cons of the order and applies it to the structural similarity matrix between models. In addition, this paper establishes corresponding mathematical models for the shape and structure of the model and constructs the shape similarity matrix, the surface neighborhood structure similarity matrix, and the structure similarity matrix between the source model and the target model. Finally, this paper designs and implements CAD model retrieval methods based on greedy algorithm and bat algorithm and designs experiments to compare the performance of the algorithm proposed in this paper with traditional algorithms. The result of the experiment shows that the algorithm proposed in this paper has obvious advantages in sports action analysis compared with the traditional algorithm. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
5. Mathematical Model and Algorithm of Multi-Index Transportation Problem in the Background of Artificial Intelligence.
- Author
-
Cao, Junfang
- Subjects
MATHEMATICAL models ,ARTIFICIAL intelligence ,MARITIME shipping ,SCIENTIFIC method ,ALGORITHMS ,CHOICE of transportation ,HUMAN activity recognition - Abstract
The development of artificial intelligence has brought rapid changes to human life and brought great convenience to human activities. The development of various modes of transportation has also brought convenience to people's travel and commodity transactions, but it has also added more issues that need to be carefully considered. Because of the diversification of transportation methods, transportation problems also arise many fields, such as air transportation, water transportation, and land transportation. The development of mathematical models and algorithms for transportation problems is also in full swing, and it is a major trend to introduce mathematical models and algorithms into the solution of transportation problems. This paper deals with the multi-index transportation problem by establishing a multi-index mathematical model and algorithm to find a scientific transportation method for the goods to be transported, so as to save the cost and time of transportation. Experiments show that the mathematical model established in this paper has high efficiency for solving the multi-index transportation problem. At the same time, the most suitable transportation method can also be selected for the transportation of goods, and the route planned by the mathematical model and algorithm can reduce the risk to 12.34%. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
6. Design of Semantic Matching Model of Folk Music in Occupational Therapy Based on Audio Emotion Analysis.
- Author
-
Ouyang, Wensi
- Subjects
SEMANTICS ,MATHEMATICAL models ,LANGUAGE & languages ,OCCUPATIONAL therapy ,CONCEPTUAL structures ,THEORY ,SOUND recordings ,DESCRIPTIVE statistics ,MUSIC ,EMOTIONS ,ALGORITHMS - Abstract
The main semantic symbol systems for people to express their emotions include natural language and music. The analysis and establishment of semantic association between language and music is helpful to provide more accurate retrieval and recommendation services for text and music. Existing researches mainly focus on the surface symbolic features and association of natural language and music, which limits the performance and interpretability of applications based on semantic association of natural language and music. Emotion is the main meaning of music expression, and the semantic range of text expression includes emotion. In this paper, the semantic features of music are extracted from audio features, and the semantic matching model of audio emotion analysis is constructed to analyze ethnic music audio emotion through feature extraction ability of deep structure. The model is based on the framework of emotional semantic matching technology and realizes the emotional semantic matching of music fragments and words through semantic emotional recognition algorithm. Multiple experiments show that when W = 0.65 , the recognition rate of multichannel fusion model is 88.42%, and the model can reasonably realize audio emotion analysis. When the spatial dimension of music data changes, the classification accuracy reaches the highest when the spatial dimension is 25. Analysing the semantic association of audio promotes the application of folk music in occupational therapy. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
7. Analysis of the Association between Teachers' Classroom Teaching Behaviors and Students' Knowledge Acceptance Based on Psychological Data Analysis.
- Author
-
Yao, Tianjin and Yang, Xiuye
- Subjects
SCHOOL environment ,DECISION trees ,TEACHER-student relationships ,TEACHING methods ,PROFESSIONS ,HEALTH occupations students ,MATHEMATICAL models ,MOTIVATION (Psychology) ,LEARNING ,TEACHERS ,THEORY ,DESCRIPTIVE statistics ,RESEARCH funding ,STUDENT attitudes ,ALGORITHMS ,VIDEO recording - Abstract
This paper adopts the method of psychological data analysis to conduct in-depth research and analysis on the correlation between teachers' classroom teaching behaviors and students' knowledge acceptance. Firstly, this paper proposes a health factor prediction model, which is specifically divided into clustering and then classification model and a clustering and classification synthesis model. The classroom learning process is coded, sampled, and quantified to obtain data on students' learning behaviors, and a visualization system based on classroom students' learning behaviors is designed and developed to record and analyze students' behaviors in the classroom learning process and grasp students' classroom learning. These two models use algorithms to fine-grained divide the dataset from the perspective of subject users and mental health factors, respectively, and then use decision tree algorithms to classify and predict the mental health factor information by the subject user base information. Second, based on the collected datasets, we designed comparison experiments to validate the clustering-then-classification model and the integrated clustering-classification model and selected the optimal model for comparison. Teachers should increase effective praise and encouragement behaviors; teachers should increase meaningful teacher-student interaction behaviors; teachers should be proficient in teaching media technology to reduce unnecessary time wastage. Strategies to enhance teachers' TPACK include enriching teachers' knowledge base of CK, TK, and PK; developing teachers' integration thinking; and enriching teachers' types of activities for integrating technology. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
8. Modeling and Optimization for a New Compliant 2-dof Stage for Locating Biomaterial Samples by an Efficient Approach of a Kinetostatic Analysis-Based Method and Neural Network Algorithm.
- Author
-
Dang, Minh Phung, Le, Hieu Giang, Van, Minh Nhut, Chau, Ngoc Le, and Dao, Thanh-Phong
- Subjects
ARTIFICIAL neural networks ,DEGREES of freedom ,ALGORITHMS ,ARTIFICIAL intelligence ,MATHEMATICAL models - Abstract
The nanoindentation technique is employed to characterize the behaviors of biomaterials. Nevertheless, there is a lack of development of a miniaturized precise positioner for in situ nanoindentation. Besides, modeling behaviors of the positioner are restricted due to its complex kinematic characteristics. Therefore, this paper proposes a novel compliant two degrees of freedom (dof) stage for positioning a biomaterial sample in in situ nanoindentation. In addition, a new modeling and dimensional optimization synthesis method of the stage is developed. The proposed effective methodology is developed based on a kinetostatic analysis-based calculation method, the Lagrange approach, and a neural network algorithm. With an increased advance in artificial intelligence, a neural network algorithm is proposed to extend the applicability of artificial neural networks in optimizing the parameters of the stage. First, the 2-dof stage is built via a combination of an eight-lever displacement amplifier and a symmetric parallelogram mechanism. Second, a chain of mathematical equations of the 2-dof stage is constructed using a kinetostatic analysis-based method to calculate the ratio of displacement amplification and the input stiffness of the 2-dof stage. Then, the Lagrange method is utilized to formulate the dynamic equation of the 2-dof stage. Finally, a neural network algorithm is adopted to maximize the natural first frequency of the proposed stage. The optimal results determined that the frequency of the stage can achieve a high value of 112.0995 Hz. Besides, the formed mathematical models were relatively precise by comprising the simulation verifications. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
9. Artificial Intelligence-Based Prediction of Individual Differences in Psychological Occupational Therapy Intervention Guided by the Realization of Occupational Values.
- Author
-
Jin, Hongmei, Pang, Yu, Du, Xiaohui, and Shi, Leilei
- Subjects
PROFESSIONAL ethics ,SUPPORT vector machines ,RESEARCH ,STATISTICS ,ANALYSIS of variance ,SAMPLE size (Statistics) ,ATTITUDE testing ,MATHEMATICAL models ,SELF-management (Psychology) ,TIME ,ARTIFICIAL intelligence ,MENTAL health ,SOCIAL capital ,COGNITION ,HEALTH status indicators ,OCCUPATIONAL therapy ,JOB satisfaction ,THEORY ,PREDICTION models ,ARTIFICIAL neural networks ,MENTAL illness ,PSYCHOTHERAPY ,ALGORITHMS - Abstract
As the competition between enterprises intensifies, employees have witnessed a decline of psychological health year by year and severe anxiety and depression. To ensure the normal work of employees, it is important to implement psychological occupational therapy intervention (POTI). The previous studies on corporate occupational values focus on the behavioral variables and attitude variables related to occupations. The research paradigm does not suit a specific group of employees. Therefore, this paper explores the individual differences in POTI guided by the realization of occupational values. For a specific group of employees, the correlations of the psychological problems with job attitude, job involvement, and psychological health level were reasoned logically, a theoretical model was established, and the full-model map was plotted to illustrate the influence of the realization of occupational values over POTI. Then, the evaluation data on the psychological intervention effect of 2,800 employees were explored based on multikernel learning, and an individual difference prediction model was constructed through multikernel learning. Finally, the predicted results of different groups of employees were compared, revealing the effectiveness of our algorithm. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
10. Simulation of Field Oriented Control Algorithm of Permanent Magnet Synchronous Motor Based on SVPWM.
- Author
-
Wang, Bin
- Subjects
PERMANENT magnet motors ,ONLINE algorithms ,ALGORITHMS ,SYNCHRONOUS electric motors ,MAGNETIC fields ,MATHEMATICAL models - Abstract
Aiming at the problems of large flux pulsation and unstable operation of permanent magnet synchronous motors affected by motor parameters and magnetic field harmonics, this paper proposes a permanent magnet synchronous motor vector control strategy based on SVPMW directional control algorithm to improve motor control performance. This control strategy realizes the effective control of the motor under harmonic interference by establishing a motor model oriented along the air gap magnetic field and the SVPMW regulator algorithm. At the same time, an online query algorithm for current reference values based on mathematical models is established to achieve fast dynamic response of the motor. A simulation model of directional control is established in MATLAB/Simulink. The simulation results show that the modeling method can effectively reduce the interference of harmonics on the flux linkage. It proves that under the interference of harmonics, the directional control of this algorithm has a better control effect, which is practical. The design and debugging of the motor control system provide the basis and ideas. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
11. A Mixed Decision Strategy for Freight and Passenger Transportation in Metro Systems.
- Author
-
Ye, Yutao, Guo, Junhua, and Yan, Lixin
- Subjects
FREIGHT & freightage ,PASSENGER traffic ,SEARCH algorithms ,ALGORITHMS ,MATHEMATICAL models - Abstract
This paper proposes a mixed decision strategy for freight and passenger transportation in metro systems during off-peak hours (MTS-OPH). The definition of the mixed decision strategy is proposed, and fixed and flexible loading modes are considered for different passenger flow volumes. A mathematical model of the MTS-OPH is proposed and solved using an improved variable neighborhood search algorithm. Case studies demonstrate the performance and applicability of the proposed model and algorithm, and the MTS-OPH is discussed for different delivery distances, passenger flows, and metro network types. The proposed strategy is suitable for long-distance delivery, and the proposed model framework can be applied to different types of metro networks with different levels of complexity. The mixed decision strategy provides a decision support tool for metro and freight companies and can propose corresponding solutions according to different passenger flows. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
12. Guidance, Navigation, and Control for Fixed-Wing UAV.
- Author
-
Israr, Amber, Alkhammash, Eman H., and Hadjouni, Myriam
- Subjects
VERTICALLY rising aircraft ,MODULAR coordination (Architecture) ,ALTITUDES ,NAVIGATION ,ALGORITHMS ,MATHEMATICAL models - Abstract
The purpose of this paper is to develop a fixed-wing aircraft that has the abilities of both vertical take-off (VTOL) and a fixed-wing aircraft. To achieve this goal, a prototype of a fixed-wing gyroplane with two propellers is developed and a rotor can maneuver like a drone and also has the ability of vertical take-off and landing similar to a helicopter. This study provides guidance, navigation, and control algorithm for the gyrocopter. Firstly, this study describes the dynamics of the fixed-wing aircraft and its control inputs, i.e., throttle, blade pitch, and thrust vectors. Secondly, the inflow velocity, the forces acting on the rotor blade, and the factors affecting the rotor speed are analyzed. Afterward, the mathematical models of the rotor, dual engines, wings, and vertical and horizontal tails are presented. Later, the flight control strategy using a global processing system (GPS) module is designed. The parameters that are examined are attitude, speed, altitude, turn, and take-off control. Lastly, hardware in the loop (HWIL) based simulations proves the effectiveness and robustness of the navigation guidance and control mechanism. The simulations confirm that the proposed novel mechanism is robust and satisfies mission requirements. The gyrocopter remains stable during the whole flight and maneuvers the designated path efficiently. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
13. Mathematical Model Design of the Traditional Dress Recognition Algorithm Based on Digital Watermarking Technology.
- Author
-
Wang, Yue, Li, Wei, and Zhang, Yaojun
- Subjects
WATERMARKS ,DIGITAL watermarking ,ETHNIC costume ,ALGORITHMS ,DRESSMAKING ,MATHEMATICAL models - Abstract
According to the characteristics of traditional clothing, clothing identification is studied, and clothing identification and clothing culture learning are effectively combined to find a new method for the inheritance of national culture and strive to make contributions to the inheritance of national culture. According to the requirement of the traditional garment identification watermark monitoring system, a self-synchronous digital watermarking algorithm is designed and implemented. Watermark is embedded in the time domain, and feature information is extracted from traditional clothing by means of mean filtering and replaced by watermark to achieve the purpose of embedding information. Blind detection is realized without the participation of the original image. The difference between the traditional costume embedded with watermark and the original traditional costume is almost imperceptible. It can effectively resist synchronous attacks including clipping and time shifting, showing good robustness. Imperceptibility and robustness can be adjusted freely by embedding strength. The HOG + SVM algorithm is applied to minority clothing classification and recognition. By comparing different classifiers, it is concluded that the classifier trained by the support vector machine algorithm has the best classification effect on ethnic clothing. In order to improve the classification effect, the classical algorithm of color, texture, and shape feature extraction was combined with SVM to conduct experiments on the clothing database collected and sorted out in Yunnan ethnic minority communities, and finally, we verified that the HOG feature combined with the SVM classification algorithm achieved good results in the classification of ethnic clothing. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
14. HS-MOEA/D: An Oriented Algorithm for Delay and Reliability VNF-SC Deployment.
- Author
-
Xuan, Hejun, You, Lei, Liu, Zhenghui, Li, Yanling, and Yang, Xiaokai
- Subjects
END-to-end delay ,VIRTUAL networks ,ALGORITHMS ,MATHEMATICAL models ,TELECOMMUNICATION ,MULTICASTING (Computer networks) ,5G networks ,DECOMPOSITION method ,QUALITY function deployment - Abstract
Network function virtualization (NFV) technology can realize on-demand distribution of network resources and improve network flexibility. It has become one of the key technologies for next-generation communications. Virtual network function service chain (VNF-SC) deployment is an important problem faced by network function virtualization technology. In this paper, the problem, VNF deployment for VNF-SC, is investigated. First, a two-objective mathematical model, which maximizes balancing and reliability of SFC, is established. In this model, VNFs are divided into two classes, i.e., part of required VNFs in each VNF-SC is dependent, others are independent. Second, harmony search-based MOEA/D (HS-MOEA/D) is proposed to solve the model effectively. In HS-MOEA/D, Chebyshev decomposition mechanism is used to transform multiobjective optimization problem into a series of single-objective optimization subproblems. A new evolutionary strategy is deeply studied in order to propose a new harmony search (HS) algorithm. Finally, to show high performance of the proposed algorithm, a large number of experiments are conducted. The simulation results show that the proposed algorithm enhances the reliability of SFC and reduces the end-to-end delay. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
15. HS-MOEA/D: An Oriented Algorithm for Delay and Reliability VNF-SC Deployment.
- Author
-
Xuan, Hejun, You, Lei, Liu, Zhenghui, Li, Yanling, and Yang, Xiaokai
- Subjects
END-to-end delay ,VIRTUAL networks ,ALGORITHMS ,MATHEMATICAL models ,TELECOMMUNICATION ,MULTICASTING (Computer networks) ,5G networks ,DECOMPOSITION method ,QUALITY function deployment - Abstract
Network function virtualization (NFV) technology can realize on-demand distribution of network resources and improve network flexibility. It has become one of the key technologies for next-generation communications. Virtual network function service chain (VNF-SC) deployment is an important problem faced by network function virtualization technology. In this paper, the problem, VNF deployment for VNF-SC, is investigated. First, a two-objective mathematical model, which maximizes balancing and reliability of SFC, is established. In this model, VNFs are divided into two classes, i.e., part of required VNFs in each VNF-SC is dependent, others are independent. Second, harmony search-based MOEA/D (HS-MOEA/D) is proposed to solve the model effectively. In HS-MOEA/D, Chebyshev decomposition mechanism is used to transform multiobjective optimization problem into a series of single-objective optimization subproblems. A new evolutionary strategy is deeply studied in order to propose a new harmony search (HS) algorithm. Finally, to show high performance of the proposed algorithm, a large number of experiments are conducted. The simulation results show that the proposed algorithm enhances the reliability of SFC and reduces the end-to-end delay. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
16. Integrated Optimization Method of IPPS under TOU and Tiered Electricity Price.
- Author
-
Xu, Erbao, Li, Yan, Yang, Mingshun, Wang, Zhenyu, Liu, Yirou, and Han, Jiali
- Subjects
ELECTRICITY pricing ,MATHEMATICAL models ,MATHEMATICAL optimization ,PRODUCTION planning ,ALGORITHMS ,ELECTRIC power consumption - Abstract
Energy-saving production is one of the issues that must be paid attention to by today's manufacturing enterprises. Aiming at the problem of integrated process planning and scheduling (IPPS) in the manufacturing process, considering Time-of-Use (TOU) and tiered electricity price, this paper systematically studies the energy-saving scheduling problem in order to reduce the power consumption in processing and production. To establish the multiobjective optimization mathematical model of the problem, the load balancing problem of the equipment is considered, the minimization of the power consumption and the maximum load of the equipment are taken as the optimization objectives. Then, considering the constraints of resource and multiprocess, the switching strategy of the equipment in idle time is introduced, including shutdown and restart operations. In order to solve the model easily, a multiobjective firefly algorithm (MOFA) based on five-layer coding is designed, and the elite strategy is introduced to protect the excellent firefly individuals in the iterative population. Finally, through a specific example, the Pareto solution set is obtained, which provides a reference scheme for decision-makers, and verifies the correctness of the model and the effectiveness of the algorithm. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
17. Reconstruction of Shredded Paper Documents by Feature Matching.
- Author
-
Peng Li, Xi Fang, Lianglu Pan, Yi Piao, and Mengjun Jiao
- Subjects
TEXTURE analysis (Image processing) ,FEATURE extraction ,ALGORITHMS ,MATHEMATICAL models ,IMAGE reconstruction - Abstract
Splicing the shredded paper means the technology that, according the paper, which has been shredded to design a particular Algorithm to splice and recover the original paper. This paper introduced the algorithm of splicing the shredded paper based on the matching to texture feature. By means of this algorithm, we modeled for the problem of splicing the shredded paper and solved it. And, we used the algorithm to splice both pieces of English shredded paper and Chinese shredded paper. The recovered paper had proved the accuracy of the algorithm. [ABSTRACT FROM AUTHOR]
- Published
- 2014
- Full Text
- View/download PDF
18. Modelling and Solving Rescheduling Problems in Dynamic Permutation Flow Shop Environments.
- Author
-
Valledor, Pablo, Gomez, Alberto, Priore, Paolo, and Puente, Javier
- Subjects
FLOW shops ,MATHEMATICAL models ,PROBLEM solving ,PERMUTATIONS ,ALGORITHMS - Abstract
The aim of this paper is to analyse, model, and solve the rescheduling problem in dynamic permutation flow shop environments while considering several criteria to optimize. Searching optimal solutions in multiobjective optimization problems may be difficult as these objectives are expressing different concepts and are not directly comparable. Thus, it is not possible to reduce the problem to a single-objective optimization, and a set of efficient (nondominated) solutions, a so-called Pareto front, must be found. Moreover, in manufacturing environments, disruptive changes usually emerge in scheduling problems, such as machine breakdowns or the arrival of new jobs, causing a need for fast schedule adaptation. In this paper, a mathematical model for this type of problem is proposed and a restarted iterated Pareto greedy (RIPG) metaheuristic is used to find the optimal Pareto front. To demonstrate the appropriateness of this approach, the algorithm is applied to a benchmark specifically designed in this study, considering three objective functions (makespan, total weighted tardiness, and steadiness) and three classes of disruptions (appearance of new jobs, machine faults, and changes in operational times). Experimental studies indicate the proposed approach can effectively solve rescheduling tasks in a multiobjective environment. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
19. Research on Mathematical Model of Cost Budget in the Early Stage of Assembly Construction Project Based on Improved Neural Network Algorithm.
- Author
-
Lin, Xin and Lu, Yinan
- Subjects
CONSTRUCTION projects ,SCAFFOLDING ,ALGORITHMS ,MATHEMATICAL models ,ARTIFICIAL neural networks - Abstract
In view of the poor performance of the original mathematical model of assembly construction project precost budget, a mathematical model of assembly construction project precost budget based on improved neural network algorithm is proposed. This paper investigates the cost content of assembly construction project and analyzes its early cost. It finds that the early cost of assembly construction project includes component production cost, transportation component cost, and installation component cost. Based on the improved neural network algorithm to build an improved neural network model, the improved neural network model to mine the cost data in the early stage of assembly construction project is used. In this paper, the earned value variable is introduced to transform the project duration and project cost in the early stage of the prefabricated construction project into quantifiable cost data, and the earned value analysis method is used to estimate the implementation cost of the prefabricated construction project. According to the result of cost estimation, the mathematical model of precost budget of prefabricated construction project is built based on the project parameters. In order to prove that the cost budget performance of the mathematical model based on the improved neural network algorithm in the early stage of assembly construction project is better, the original mathematical model is compared with the mathematical model, the experimental results show that the cost budget performance of the model is better than the original model, and the cost budget performance is improved. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
20. A New Hybrid PSS Optimization Method Based on Improved Active Set Algorithm.
- Author
-
Liu, Xiang-Yu, He, Yu-Ling, and Yao, Jian
- Subjects
MATHEMATICAL optimization ,ALGORITHMS ,MATHEMATICAL models ,POWER system simulation ,ENGINEERING mathematics - Abstract
This paper proposes a new hybrid optimization method for the phase-frequency characteristics of the double input power system stabilizer (PSS) based on the improved active set algorithm. This method takes the effect of the filtering section optimization on the parameter improvement into account, and the optimized model focuses on the minimum residual sum of squares between the actual and the target phase-frequency characteristics. The result shows that the improved parameters obtained from the proposed method provide much better phase-frequency characteristics than the widely used engineering parameters. The comparison between the proposed method and the typical commercial software indicates the universal superiority of the proposed method. And the studies on the impact of considering the filter section optimization on the phase-frequency improvement show that taking the filter section optimization into account will be beneficial for the phase-frequency improvement, though in application to the PSS2A model and the PSS2B model there are some differences. The achievements obtained in this paper provide a significant reference for the practical PSS parameter modification and improvement. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
21. Spiculation Sign Recognition in a Pulmonary Nodule Based on Spiking Neural P Systems.
- Author
-
Qiu, Shi, Sun, Jingtao, Zhou, Tao, Gao, Guilong, He, Zhenan, and Liang, Ting
- Subjects
BRAIN physiology ,ALGORITHMS ,DIAGNOSTIC imaging ,MATHEMATICAL models ,ARTIFICIAL neural networks ,QUALITY assurance ,THREE-dimensional imaging ,THEORY ,COMPUTER-aided diagnosis ,SOLITARY pulmonary nodule - Abstract
The spiculation sign is one of the main signs to distinguish benign and malignant pulmonary nodules. In order to effectively extract the image feature of a pulmonary nodule for the spiculation sign distinguishment, a new spiculation sign recognition model is proposed based on the doctors' diagnosis process of pulmonary nodules. A maximum density projection model is established to fuse the local three-dimensional information into the two-dimensional image. The complete boundary of a pulmonary nodule is extracted by the improved Snake model, which can take full advantage of the parallel calculation of the Spike Neural P Systems to build a new neural network structure. In this paper, our experiments show that the proposed algorithm can accurately extract the boundary of a pulmonary nodule and effectively improve the recognition rate of the spiculation sign. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
22. An Improved Genetic-Shuffled Frog-Leaping Algorithm for Permutation Flowshop Scheduling.
- Author
-
Wu, Peiliang, Yang, Qingyu, Chen, Wenbai, Mao, Bingyi, and Yu, Hongnian
- Subjects
ALGORITHMS ,PERMUTATIONS ,SCHEDULING ,INDUSTRY 4.0 ,GENETIC algorithms ,MATHEMATICAL models - Abstract
Due to the NP-hard nature, the permutation flowshop scheduling problem (PFSSP) is a fundamental issue for Industry 4.0, especially under higher productivity, efficiency, and self-managing systems. This paper proposes an improved genetic-shuffled frog-leaping algorithm (IGSFLA) to solve the permutation flowshop scheduling problem. In the proposed IGSFLA, the optimal initial frog (individual) in the initialized group is generated according to the heuristic optimal-insert method with fitness constrain. The crossover mechanism is applied to both the subgroup and the global group to avoid the local optimal solutions and accelerate the evolution. To evolve the frogs with the same optimal fitness more outstanding, the disturbance mechanism is applied to obtain the optimal frog of the whole group at the initialization step and the optimal frog of the subgroup at the searching step. The mathematical model of PFSSP is established with the minimum production cycle (makespan) as the objective function, the fitness of frog is given, and the IGSFLA-based PFSSP is proposed. Experimental results have been given and analyzed, showing that IGSFLA not only provides the optimal scheduling performance but also converges effectively. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
23. An Improved Whale Algorithm for Setting Standard Scheduled Block Time Based on the Airline Fairness.
- Author
-
Wang, Qian, Tian, Yong, Lin, Lili, Vanga, Ratnaji, and Ma, Lina
- Subjects
ALGORITHMS ,FAIRNESS ,PROCESS optimization ,WHALES ,NONLINEAR equations ,MATHEMATICAL models - Abstract
Standard scheduled flight block time (SBT) setting is of great concern for Civil Aviation Administration of China (CAAC) and airlines in China. However, the standard scheduled flight block times are set in the form of on-site meetings in practice and current literature has not provided any efficient mathematical models to calculate the flight block times fairly among the airlines. The objective of this paper is to develop and solve a mathematical model for standard SBT setting with consideration of both fairness and reliability. We use whale optimization algorithm (WOA) and an improved version of the whale optimization algorithm (IWOA) to solve the SBT setting problem. A novel nonlinear update equation of convergence factor for random iterations is used in place of the original linear one in the proposed IWOA algorithm. Experimental results show that the suggested approach is effective, and IWOA performs better than WOA in the concerned problem, whose solutions are better compared to the flight block times released by CAAC. In particular, it is interesting to find that MSE, RMSE, MAE, MAPE and Theil of the reliability in 60%–70% range are always the smallest and the average fairness of airlines is better than that of 60%–75% range. The model and solving approach presented in this article have great potential to be applied by CAAC to determine the standard SBTs strategically. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
24. Evaluation of Transportation Network Reliability under Emergency Based on Reserve Capacity.
- Author
-
Zhang, Xiongfei, Zhong, Qi, and Luo, Qin
- Subjects
TRAFFIC engineering ,ALGORITHMS ,ENGINEERING ,ALGEBRA ,MATHEMATICAL models - Abstract
There are differences between the requirements for traffic network for traffic demand in daily and emergency situations. In order to evaluate how the network designed for daily needs can meet the surging demand for emergency evacuation, the concept of emergency reliability and corresponding evaluation method is proposed. This paper constructs a bilevel programming model to describe the proposed problem. The upper level problem takes the maximum reserve capacity multiplier as the optimization objective and considers the influence of reversible lane measures taken under emergency conditions. The lower level model adopts the combined traffic distribution/assignment model with capacity limits, to describe evacuees' path and shelter choice behavior under emergency conditions and take into account the traits of crowded traffic. An iterative optimization method is proposed to solve the upper level model, and the lower level model is transformed into a UE assignment problem with capacity limits over a network of multiple origins and single destination, by adding a dummy node and several dummy links in the network. Then a dynamic penalty function algorithm is used to solve the problem. In the end, numerical studies and results are provided to demonstrate the rationality of the proposed model and feasibility of the proposed solution algorithms. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
25. An Algorithm of l1-Norm and l0-Norm Regularization Algorithm for CT Image Reconstruction from Limited Projection.
- Author
-
Li, Xiezhang, Feng, Guocan, and Zhu, Jiehua
- Subjects
ALGORITHMS ,COMPUTED tomography ,DIAGNOSTIC imaging ,DIGITAL image processing ,MATHEMATICAL models ,RESEARCH evaluation ,THEORY - Abstract
The l 1 -norm regularization has attracted attention for image reconstruction in computed tomography. The l 0 -norm of the gradients of an image provides a measure of the sparsity of gradients of the image. In this paper, we present a new combined l 1 -norm and l 0 -norm regularization model for image reconstruction from limited projection data in computed tomography. We also propose an algorithm in the algebraic framework to solve the optimization effectively using the nonmonotone alternating direction algorithm with hard thresholding method. Numerical experiments indicate that this new algorithm makes much improvement by involving l 0 -norm regularization. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
26. A System Biology-Based Approach for Designing Combination Therapy in Cancer Precision Medicine.
- Author
-
Sabzpoushan, S. H.
- Subjects
TUMOR treatment ,ALGORITHMS ,BIOLOGY ,COMBINED modality therapy ,GENOMES ,MATHEMATICAL models ,DRUG development ,THEORY ,INDIVIDUALIZED medicine - Abstract
In this paper, we have used an agent-based stochastic tumor growth model and presented a mathematical and theoretical perspective to cancer therapy. This perspective can be used to theoretical study of precision medicine and combination therapy in individuals. We have conducted a series of in silico combination therapy experiments. Based on cancer drugs and new findings of cancer biology, we hypothesize relationships between model parameters which in some cases represent individual genome characteristics and cancer drugs, i.e., in our approach, therapy players are delegated by biologically reasonable parameters. In silico experiments showed that combined therapies are more effective when players affect tumor via different mechanisms and have different physical dimensions. This research presents for the first time an algorithm as a theoretical viewpoint for the prediction of effectiveness and classification of therapy sets. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
27. A Mathematical Model and Self-Adaptive NSGA-II for a Multiobjective IPPS Problem Subject to Delivery Time.
- Author
-
Ba, Li, Yang, Mingshun, Gao, Xinqin, Liu, Yong, Han, Zhoupeng, Xu, Erbao, and Li, Yan
- Subjects
MATHEMATICAL models ,PRODUCTION planning ,DECODING algorithms ,GENETIC algorithms ,ALGORITHMS - Abstract
Process planning and scheduling are two important components of manufacturing systems. This paper deals with a multiobjective just-in-time integrated process planning and scheduling (MOJIT-IPPS) problem. Delivery time and machine workload are considered to make IPPS problem more suitable for manufacturing environments. The earliness/tardiness penalty, maximum machine workload, and total machine workload are objectives that are minimized. The decoding method is a crucial part that significantly influences the scheduling results. We develop a self-adaptive decoding method to obtain better results. A nondominated sorting genetic algorithm with self-adaptive decoding (SD-NSGA-II) is proposed for solving MOJIT-IPPS. Finally, the model and algorithm are proven through an example. Furthermore, different scale examples are tested to prove the good performance of the proposed method. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
28. Poly(vinyl alcohol boric acid)-Diclofenac Sodium Salt Drug Delivery Systems: Experimental and Theoretical Studies.
- Author
-
Ailincai, Daniela, Dorobanțu, Alexandra Maria, Dima, Bogdan, Irimiciuc, Ștefan Andrei, Lupașcu, Cristian, Agop, Maricel, and Olguta, Orzan
- Subjects
DRUG delivery systems ,BORIC acid ,SODIUM salts ,ATOMIC force microscopy ,PHARMACOKINETICS ,POLYSTYRENE ,DICLOFENAC ,MATHEMATICAL models ,MICROSCOPY ,THEORY ,INFRARED spectroscopy ,ENZYME inhibitors ,ALGORITHMS ,DOSAGE forms of drugs - Abstract
The main aim of the paper was to simulate the drug release by a multifractal theoretical model, as a valuable method to assess the drug release mechanism. To do this, drug delivery films were prepared by mixing poly(vinyl alcohol boric acid) (PVAB) and diclofenac (DCF) sodium salt drug in different mass ratios from 90/10 to 70/30, in order to obtain drug delivery systems with different releasing rates. The different drug content of the three systems was confirmed by energy-dispersive spectroscopy (EDAX) analysis, and the encapsulation particularities were investigated by scanning electron microscopy (SEM), atomic force microscopy (AFM), and polarized optical microscopy (POM) techniques. The ability of the PVAB matrix to anchor the DCF was assessed by Fourier transform infrared (FTIR) spectroscopy. The in vitro release of the diclofenac sodium salt from the formulations was investigated in biomimetic conditions (pH = 7.4 and 37°C) by UV-Vis spectroscopy, measuring the absorbance of the drug at 275 nm and fitting the results on a previously drawn calibration curve. An estimation of the drug release kinetics was performed by fitting three traditional mathematical models on experimental release data. Further, the drug delivery was simulated by the fractal theory of motion, in which the release dynamics of the polymer-drug complex system is described through various Riccati-type "regimes." To explain such dynamics involved multifractal self-modulation in the form of period doubling, quasiperiodicity, intermittency, etc., as well as multifractal self-modulation of network type. Standard release dynamics were explained by multifractal behaviors of temporary kink type. The good correlation between the traditional mathematical models and the new proposed theoretical model demonstrated the validity of the multifractal model for the investigation of the drug release. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
29. An Improved Shuffled Frog Leaping Algorithm for Multiload AGV Dispatching in Automated Container Terminals.
- Author
-
Ma, Xiaoyang, Bian, Yongming, and Gao, Fei
- Subjects
CONTAINERIZATION ,CONTAINER terminals ,FROGS ,AUTOMATED guided vehicle systems ,ALGORITHMS ,MATHEMATICAL models - Abstract
Multiload AGVs, which can carry more than one container at a time, are widely used in automated container terminals. The dispatching decisions for multiload AGVs serving in automated container terminals on the target of minimum travel distance are significant in the process of container transportation in terms of improving operating efficiency. Previous work usually focused on AGVs working in a single-carrier mode, which was not only inconsistent with actual circumstances but also a waste of resources. In this paper, we establish a new mathematical model to describe multiload AGVs operating in automated container terminals, which is closer to the actual situation in real terminals. Based on this improved model, we propose a priority rule-based algorithm, termed as shuffled frog leaping algorithm with a mutant process (SFLAMUT), which can increase the diversity of the population and improve the convergence rate. Experiments were carried out based on data generated randomly according to the working properties of container terminals, and it is observed that the proposed SFLAMUT presents an effective and efficient exploration process and yields promising results in solving the proposed mathematical model. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
30. An Approach to Ship Deck Arrangement Optimization Problem Using an Improved Multiobjective Hybrid Genetic Algorithm.
- Author
-
Wang, Hao and Chen, Shunhuai
- Subjects
SHIP models ,GENETIC algorithms ,ALGORITHMS ,DETERMINISTIC algorithms ,SHIPS ,MATHEMATICAL models ,NAVAL architecture - Abstract
Ship deck arrangement design is about determining the positions and dimensions of arranged objects. This paper presents the mathematical model for the ship deck arrangement optimization problem statement and how the individual's objective and constraint functions are computed. Moreover, an improved multiobjective hybrid genetic algorithm is redesigned to solve this complex nondeterministic problem and generate a set of diverse and rational deck arrangements in the early stage of ship design. An adaptive crossover operator and a novel topological replace operator invoked in this algorithm are described. Finally, the proposed algorithm is tested on a main deck arrangement optimization of an underwater detection ship. In the validation tests, the proposed algorithm is compared to the standard NSGA-II to determine its ability to produce a set of diverse and rational deck arrangements. Subsequently, the performance tests are used to determine the ability of the algorithm to work with the highly constrained arrangement problems and the efficiency of the adaptive crossover and topological replace operators. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
31. A New Multiobjective Time-Cost Trade-Off for Scheduling Maintenance Problem in a Series-Parallel System.
- Author
-
Tavassoli, Leyla Sadat, Massah, Reza, Montazeri, Arsalan, Mirmozaffari, Mirpouya, Jiang, Guang-Jun, and Chen, Hong-Xia
- Subjects
EVOLUTIONARY algorithms ,ALGORITHMS ,MAINTENANCE costs ,GENETIC algorithms ,PRODUCTION scheduling ,MATHEMATICAL models - Abstract
In this paper, a modified model of Nondominated Sorting Genetic Algorithm 2 (NSGA-II), which is one of the Multiobjective Evolutionary Algorithms, is proposed. This algorithm is a new model designed to make a trade-off between minimizing the cost of preventive maintenance (PM) and minimizing the time taken to perform this maintenance for a series-parallel system. In this model, the limitations of labor and equipment of the maintenance team and the effects of maintenance issues on manufacturing problems are also considered. In the mathematical model, finding the appropriate objective functions for the maintenance scheduling problem requires all maintenance costs and failure rates to be integrated. Additionally, the effects of production interruption during preventive maintenance are added to objective functions. Furthermore, to make a better performance compared with a regular NSGA-II algorithm, we proposed a modified algorithm with a repository to keep more unacceptable solutions. These solutions can be modified and changed with the proposed mutation algorithm to acceptable solutions. In this algorithm, modified operators, such as simulated binary crossover and polynomial mutation, will improve the algorithm to generate convergence and uniformly distributed solutions with more diverse solutions. Finally, by comparing the experimental solutions with the solutions of two Strength Pareto Evolutionary Algorithm 2 (SPEA2) and regular NSGA-II, MNSGA-II generates more efficient and uniform solutions than the other two algorithms. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
32. Identification of Methylation Signatures and Rules for Sarcoma Subtypes by Machine Learning Methods.
- Author
-
Ren, Jingxin, Zhou, XianChao, Guo, Wei, Feng, KaiYan, Huang, Tao, and Cai, Yu-Dong
- Subjects
BIOMARKERS ,DECISION trees ,MATHEMATICAL models ,MACHINE learning ,RANDOM forest algorithms ,DNA methylation ,GENE expression ,THEORY ,SARCOMA ,EARLY diagnosis ,ALGORITHMS ,EPIGENOMICS - Abstract
Sarcoma, the second common type of solid tumor in children and adolescents, has a wide variety of subtypes that are often not properly diagnosed at an early stage, leading to late metastases and causing serious loss of life and property to patients and families. It exhibits a high degree of heterogeneity at the cellular, molecular, and epigenetic levels, where DNA methylation has been proposed to play a role in the diagnosis of sarcoma subtypes. Thus, this study is aimed at finding potential biomarkers at the DNA methylation level to distinguish different sarcoma subtypes. A machine learning process was designed to analyse sarcoma samples, each of which was represented by lots of methylation sites. Irrelevant sites were removed using the Boruta method, and remaining sites related to the target variables were kept for further analyses. Afterward, three feature ranking methods (LASSO, LightGBM, and MCFS) were adopted to rank these features, and six classification models were constructed by combining incremental feature selection and two classification algorithms (decision tree and random forest). Among these models, the performance of RF model was higher than that of DT model under all three ranking conditions. The specific expression of genes obtained from the annotation of highly correlated methylation site features, such as PRKAR1B, INPP5A, and GLI3, was proven to be associated with sarcoma by publications. Moreover, the quantitative rules obtained by decision tree algorithm helped us to understand the essential differences between various sarcoma types and classify sarcoma subtypes, providing a new means of clinical identification and determining new therapeutic targets. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
33. Detection of Pancreatic Cancer in CT Scan Images Using PSO SVM and Image Processing.
- Author
-
Ansari, Arshiya S., Zamani, Abu Sarwar, Mohammadi, Mohammad Sajid, Meenakshi, Ritonga, Mahyudin, Ahmed, Syed Sohail, Pounraj, Devabalan, and Kaliyaperumal, Karthikeyan
- Subjects
PANCREATIC tumors ,DIGITAL image processing ,MATHEMATICAL models ,EARLY detection of cancer ,DIAGNOSTIC imaging ,THEORY ,COMPUTED tomography ,SENSITIVITY & specificity (Statistics) ,ALGORITHMS ,DIGITAL diagnostic imaging - Abstract
A diagnosis of pancreatic cancer is one of the worst cancers that may be received anywhere in the world; the five-year survival rate is very less. The majority of cases of this condition may be traced back to pancreatic cancer. Due to medical image scans, a significant number of cancer patients are able to identify abnormalities at an earlier stage. The expensive cost of the necessary gear and infrastructure makes it difficult to disseminate the technology, putting it out of the reach of a lot of people. This article presents detection of pancreatic cancer in CT scan images using machine PSO SVM and image processing. The Gaussian elimination filter is utilized during the image preprocessing stage of the removal of noise from images. The K means algorithm uses a partitioning technique to separate the image into its component parts. The process of identifying objects in an image and determining the regions of interest is aided by image segmentation. The PCA method is used to extract important information from digital photographs. PSO SVM, naive Bayes, and AdaBoost are the algorithms that are used to perform the classification. Accuracy, sensitivity, and specificity of the PSO SVM algorithm are better. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
34. Research on Three-Phase Unbalanced Commutation Strategy Based on the Spotted Hyena Optimizer Algorithm.
- Author
-
Zhang, Yi, Sun, XianBo, Zhu, Li, Yang, ShengXin, and Sun, YueFei
- Subjects
ALGORITHMS ,MATHEMATICAL models - Abstract
Aimed at that ubiquitous three-phase unbalance problem in low-voltage distribution networks, the spotted hyena optimizer (SHO) algorithm is used to optimize the commutation strategy of the three-phase load unbalance. A multitarget swapping mathematical model was designed, and the objective was quickly resolved by relying on the excellent commutation strategy of the SHO. Finally, a case analysis was carried out on the data of a station area in Enshi, Hubei Province, and the results verify this swapping strategy can effectively reduce the unbalance rate. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
35. Applications of Artificial Intelligence in Ophthalmology: General Overview.
- Author
-
Lu, Wei, Tong, Yan, Yu, Yue, Xing, Yiqiao, Chen, Changzheng, and Shen, Yin
- Subjects
EYE diseases ,ALGORITHMS ,ARTIFICIAL intelligence ,DATABASE management ,MATHEMATICAL models ,OPHTHALMOLOGY ,WORKFLOW ,THEORY ,DIAGNOSIS - Abstract
With the emergence of unmanned plane, autonomous vehicles, face recognition, and language processing, the artificial intelligence (AI) has remarkably revolutionized our lifestyle. Recent studies indicate that AI has astounding potential to perform much better than human beings in some tasks, especially in the image recognition field. As the amount of image data in imaging center of ophthalmology is increasing dramatically, analyzing and processing these data is in urgent need. AI has been tried to apply to decipher medical data and has made extraordinary progress in intelligent diagnosis. In this paper, we presented the basic workflow for building an AI model and systematically reviewed applications of AI in the diagnosis of eye diseases. Future work should focus on setting up systematic AI platforms to diagnose general eye diseases based on multimodal data in the real world. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
36. A Force-Directed Algorithm for Drawing Directed Graphs Symmetrically.
- Author
-
Xu, Taihua, Yang, Jie, and Gou, Guanglei
- Subjects
DIRECTED graphs ,SUBGRAPHS ,ALGORITHMS ,GEOMETRIC vertices ,MATHEMATICAL models - Abstract
Symmetry is one of the most important aesthetic criteria on graph drawing. It is quite necessary to measure the extent to which the drawings can be considered symmetric. For this purpose, a symmetric metric based on vertex coordinate calculation is proposed in this paper. It is proven theoretically and experimentally that the proposed metric is robust to contraction, expansion, and rotation of drawings. This robustness conforms to human perception of symmetry. Star-subgraphs and cycles are two common structures in digraphs. Both of them have inherent symmetry which should be displayed in drawings. For this purpose, a force-directed algorithm named FDS is proposed which can draw star-subgraphs and cycles as symmetrically as possible. FDS algorithm draws cycles as circles whose positions are fixed to provide a scaffolding for overall layout, renders non-leaf vertices by a standard force-directed layout, and places leaf vertices on concentric circles via a deterministic strategy. A series of experiments are carried out to test FDS algorithm. The results show that FDS algorithm draws digraphs more symmetrically than the existing state-of-the-art algorithms and performs efficiency comparable to O(nlogn) YFHu algorithm. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
37. Mathematical Models in Humanitarian Supply Chain Management: A Systematic Literature Review.
- Author
-
Habib, Muhammad Salman, Lee, Young Hae, and Memon, Muhammad Saad
- Subjects
MATHEMATICAL models ,SUPPLY chain management ,LITERATURE reviews ,ALGORITHMS ,MATHEMATICAL analysis - Abstract
In the past decade the humanitarian supply chain (HSC) has attracted the attention of researchers due to the increasing frequency of disasters. The uncertainty in time, location, and severity of disaster during predisaster phase and poor conditions of available infrastructure during postdisaster phase make HSC operations difficult to handle. In order to overcome the difficulties during these phases, we need to assure that HSC operations are designed in an efficient manner to minimize human and economic losses. In the recent times, several mathematical optimization techniques and algorithms have been developed to increase the efficiency of HSC operations. These techniques and algorithms developed for the field of HSC motivate the need of a systematic literature review. Owing to the importance of mathematical modelling techniques, this paper presents the review of the mathematical contributions made in the last decade in the field of HSC. A systematic literature review methodology is used for this paper due to its transparent procedure. There are two objectives of this study: the first one is to conduct an up-to-date survey of mathematical models developed in HSC area and the second one is to highlight the potential research areas which require attention of the researchers. [ABSTRACT FROM AUTHOR]
- Published
- 2016
- Full Text
- View/download PDF
38. Axis-Guided Vessel Segmentation Using a Self-Constructing Cascade-AdaBoost-SVM Classifier.
- Author
-
Hu, Xin, Cheng, Yuanzhi, Ding, Deqiong, and Chu, Dianhui
- Subjects
CAROTID artery surgery ,ALGORITHMS ,ARTIFICIAL intelligence ,VASCULAR surgery ,MATHEMATICAL models ,RESEARCH evaluation ,THEORY ,SYSTEMS development ,COMPUTER-assisted surgery - Abstract
One major limiting factor that prevents the accurate delineation of vessel boundaries has been the presence of blurred boundaries and vessel-like structures. Overcoming this limitation is exactly what we are concerned about in this paper. We describe a very different segmentation method based on a cascade-AdaBoost-SVM classifier. This classifier works with a vessel axis + cross-section model, which constrains the classifier around the vessel. This has the potential to be both physiologically accurate and computationally effective. To further increase the segmentation accuracy, we organize the AdaBoost classifiers and the Support Vector Machine (SVM) classifiers in a cascade way. And we substitute the AdaBoost classifier with the SVM classifier under special circumstances to overcome the overfitting issue of the AdaBoost classifier. The performance of our method is evaluated on synthetic complex-structured datasets, where we obtain high overlap ratios, around 91%. We also validate the proposed method on one challenging case, segmentation of carotid arteries over real clinical datasets. The performance of our method is promising, since our method yields better results than two state-of-the-art methods on both synthetic datasets and real clinical datasets. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
39. A Hybrid Strategy of Differential Evolution and Modified Particle Swarm Optimization for Numerical Solution of a Parallel Manipulator.
- Author
-
Mao, Bingyan, Xie, Zhijiang, Wang, Yongbo, Handroos, Heikki, and Wu, Huapeng
- Subjects
PARALLEL robots ,DIFFERENTIAL evolution ,PARTICLE swarm optimization ,KINEMATICS ,ALGORITHMS ,ALGEBRAIC equations ,MATHEMATICAL models - Abstract
This paper presents a hybrid strategy combined with a differential evolution (DE) algorithm and a modified particle swarm optimization (PSO), denominated as DEMPSO, to solve the nonlinear model of the forward kinematics. The proposed DEMPSO takes the best advantage of the convergence rate of MPSO and the global optimization of DE. A comparison study between the DEMPSO and the other optimization algorithms such as the DE algorithm, PSO algorithm, and MPSO algorithm is performed to obtain the numerical solution of the forward kinematics of a 3-RPS parallel manipulator. The forward kinematic model of the 3-RPS parallel manipulator has been developed and it is essentially a nonlinear algebraic equation which is dependent on the structure of the mechanism. A constraint equation based on the assembly relationship is utilized to express the position and orientation of the manipulator. Five configurations with different positions and orientations are used as an example to illustrate the effectiveness of the proposed DEMPSO for solving the kinematic problem of parallel manipulators. And the comparison study results of DEMPSO and the other optimization algorithms also show that DEMPSO can provide a better performance regarding the convergence rate and global searching properties. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
40. Central Heating System Constrained Control with Input Delay Based on Neural Networks.
- Author
-
Wang, Hongwei, Tu, Fangwen, Feng, Guohui, and Ao, Xin
- Subjects
LYAPUNOV functions ,NEURAL circuitry ,COMPUTER simulation ,MATHEMATICAL models ,ALGORITHMS - Abstract
An output constrained control with input delay is proposed for a central heating system. Due to the delay of signal transmission and valves opening time, an input delay is considered into the system and an auxiliary system is employed to handle this issue by converting the delayed input into a delay-free one. Moreover, to ensure the output supply water temperature within a limited range, Barrier Lyapunov algorithm is involved to achieve desired control accuracy. Finally, external disturbance and model uncertainty are incorporated into the dynamic system and neural networks (NN) are trained in an online fashion for the compensation. The stability of the control system is guaranteed through rigorous Lyapunov analysis and the excellent control performance over traditional PID control is demonstrated via numerical simulation study. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
41. Leader-Follower Consensus of Second-Order Multiagent Systems with Absent Velocity Measurement and Time Delay.
- Author
-
Yang, Panpan, Tang, Ye, Yan, Maode, and Zuo, Lei
- Subjects
VELOCITY ,COMPUTER simulation ,MATHEMATICAL models ,ALGORITHMS ,MATRICES (Mathematics) - Abstract
The leader-follower consensus problem of second-order multiagent systems with both absent velocity measurement and time delay is considered. First of all, the consensus protocol is designed by introducing an auxiliary system to compensate for the unavailability of the velocity information. Then, time delay is incorporated into the consensus protocol and two cases with, respectively, constant time delay and time-varying delay are investigated. For the case of constant time delay, Lyapunov-Razumikhin theorem is deployed to obtain the sufficient conditions that guarantee the stability of the consensus algorithm. For the case of time-varying delay, the sufficient conditions are also derived by resorting to the Lyapunov-Razumkhin theorem and linear matrix inequalities (LMIs). Various numerical simulations demonstrate the correctness of the theoretical results. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
42. A Segmentation of Melanocytic Skin Lesions in Dermoscopic and Standard Images Using a Hybrid Two-Stage Approach.
- Author
-
Hwang, Yoo Na, Seo, Min Ji, and Kim, Sung Min
- Subjects
DIGITAL image processing ,MELANOMA ,MICROSCOPY ,MATHEMATICAL models ,REGRESSION analysis ,SKIN tumors ,THEORY ,DESCRIPTIVE statistics ,DATA analysis software ,ALGORITHMS - Abstract
The segmentation of a skin lesion is regarded as very challenging because of the low contrast between the lesion and the surrounding skin, the existence of various artifacts, and different imaging acquisition conditions. The purpose of this study is to segment melanocytic skin lesions in dermoscopic and standard images by using a hybrid model combining a new hierarchical K -means and level set approach, called HK-LS. Although the level set method is usually sensitive to initial estimation, it is widely used in biomedical image segmentation because it can segment more complex images and does not require a large number of manually labelled images. The preprocessing step is used for the proposed model to be less sensitive to intensity inhomogeneity. The proposed method was evaluated on medical skin images from two publicly available datasets including the PH
2 database and the Dermofit database. All skin lesions were segmented with high accuracies (>94%) and Dice coefficients (>0.91) of the ground truth on two databases. The quantitative experimental results reveal that the proposed method yielded significantly better results compared to other traditional level set models and has a certain advantage over the segmentation results of U-net in standard images. The proposed method had high clinical applicability for the segmentation of melanocytic skin lesions in dermoscopic and standard images. [ABSTRACT FROM AUTHOR]- Published
- 2021
- Full Text
- View/download PDF
43. A Variational Bayesian Superresolution Approach Using Adaptive Image Prior Model.
- Author
-
Zhao, Shengrong, Jin, Renchao, Xu, Xiangyang, Song, Enmin, and Hung, Chih-Cheng
- Subjects
IMAGE processing ,BAYESIAN analysis ,HIGH resolution imaging ,MATHEMATICAL models ,ALGORITHMS ,IMAGE reconstruction - Abstract
The objective of superresolution is to reconstruct a high-resolution image by using the information of a set of low-resolution images. Recently, the variational Bayesian superresolution approach has been widely used. However, these methods cannot preserve edges well while removing noises. For this reason, we propose a new image prior model and establish a Bayesian superresolution reconstruction algorithm. In the proposed prior model, the degree of interaction between pixels is adjusted adaptively by an adaptive norm, which is derived based on the local image features. Moreover, in this paper, a monotonically decreasing function is used to calculate and update the single parameter, which is used to control the severity of penalizing image gradients in the proposed prior model. Thus, the proposed prior model is adaptive to the local image features thoroughly. With the proposed prior model, the edge details are preserved and noises are reduced simultaneously. A variational Bayesian inference is employed in this paper, and the formulas for calculating all the variables including the HR image, motion parameters, and hyperparameters are derived. These variables are refined progressively in an iterative manner. Experimental results show that the proposed SR approach is very efficient when compared to existing approaches. [ABSTRACT FROM AUTHOR]
- Published
- 2015
- Full Text
- View/download PDF
44. Efficiency Improvements of Antenna Optimization Using Orthogonal Fractional Experiments.
- Author
-
Chen, Yen-Sheng and Ku, Ting-Yu
- Subjects
ALGORITHMS ,SIMULATION methods & models ,MATHEMATICAL models ,RADIO frequency identification systems ,IDENTIFICATION equipment - Abstract
This paper presents an extremely efficient method for antenna design and optimization. Traditionally, antenna optimization relies on nature-inspired heuristic algorithms, which are time-consuming due to their blind-search nature. In contrast, design of experiments (DOE) uses a completely different framework from heuristic algorithms, reducing the design cycle by formulating the surrogates of a design problem. However, the number of required simulations grows exponentially if a full factorial design is used. In this paper, a much more efficient technique is presented to achieve substantial time savings. By using orthogonal fractional experiments, only a small subset of the full factorial design is required, yet the resultant response surface models are still effective. The capability of orthogonal fractional experiments is demonstrated through three examples, including two tag antennas for radio-frequency identification (RFID) applications and one internal antenna for long-term-evolution (LTE) handheld devices. In these examples, orthogonal fractional experiments greatly improve the efficiency of DOE, thereby facilitating the antenna design with less simulation runs. [ABSTRACT FROM AUTHOR]
- Published
- 2015
- Full Text
- View/download PDF
45. Rolling Element Bearing Performance Degradation Assessment Using Variational Mode Decomposition and Gath-Geva Clustering Time Series Segmentation.
- Author
-
Li, Yaolong, Li, Hongru, Wang, Bing, and Gu, Hongqiang
- Subjects
ROTATING machinery ,ROLLER bearings ,BEARINGS (Machinery) ,DYNAMIC programming ,ALGORITHMS ,MATHEMATICAL models - Abstract
By focusing on the issue of rolling element bearing (REB) performance degradation assessment (PDA), a solution based on variational mode decomposition (VMD) and Gath-Geva clustering time series segmentation (GGCTSS) has been proposed. VMD is a new decomposition method. Since it is different from the recursive decomposition method, for example, empirical mode decomposition (EMD), local mean decomposition (LMD), and local characteristic-scale decomposition (LCD), VMD needs a priori parameters. In this paper, we will propose a method to optimize the parameters in VMD, namely, the number of decomposition modes and moderate bandwidth constraint, based on genetic algorithm. Executing VMD with the acquired parameters, the BLIMFs are obtained. By taking the envelope of the BLIMFs, the sensitive BLIMFs are selected. And then we take the amplitude of the defect frequency (ADF) as a degradative feature. To get the performance degradation assessment, we are going to use the method called Gath-Geva clustering time series segmentation. Afterwards, the method is carried out by two pieces of run-to-failure data. The results indicate that the extracted feature could depict the process of degradation precisely. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
- View/download PDF
46. Fair Optimization and Networks: Models, Algorithms, and Applications.
- Author
-
Ogryczak, Wlodzimierz, Luss, Hanan, Nace, Dritan, and Pióro, Michał
- Subjects
MATHEMATICAL optimization ,ALGORITHMS ,MATHEMATICAL analysis ,MATHEMATICAL models ,APPLIED mathematics - Published
- 2014
- Full Text
- View/download PDF
47. Revising Transient-Pressure Solution for Vertical Well Intersected by a Partially Penetrating Fracture with Non-Darcy Flow Effect.
- Author
-
Cui, Shuheng, Kong, Jie, Yu, Hongwei, Chen, Cheng, and Wang, Junlei
- Subjects
THREE-dimensional flow ,NONLINEAR equations ,ALGORITHMS ,ANALYTICAL solutions ,MATHEMATICAL models ,DARCY'S law - Abstract
The principle purpose of this work is to formulate an accurate mathematical model to evaluate the transient pressure behavior of a well intercepted by a partially penetrating vertical fracture (PPVF) with non-Darcy flow effect. Fracture conductivity is taken into account by coupling the three-dimensional flow in reservoir and the two-dimensional flow within fracture; the Barree-Conway model is incorporated into the model to analyze non-Darcy flow behavior in fracture, which leads to the nonlinearity of the governing equations. A high-effective iterative algorithm using a combined technique of fracture-panel discretization and dimension transform is developed to render the nonlinear equations amenable to analytical linear treatment. On the basis of the solutions, the pressure response and its derivative type curves were generated to identify the evolution of flow regimes with time. Furthermore, the influences of fracture conductivity, penetration ratio, and non-Darcy characteristic parameters on pressure response are investigated. The results show that PPVF exhibits five typical flow regimes, and analytical solutions for each flow regime are similar to that for a fully penetrating vertical fracture (FPVF) that can be correlated with the penetration ratio and apparent conductivity. The non-Darcy flow effect is found to have more significant effect on the low and moderate conductivity, especially in early-stage flow regimes. When the penetration ratio is smaller than 0.5, the pressure behavior exhibit a more remarkable variation with penetration ratio. This study provides a better insight into understanding the influence of non-Darcy flow on flow regime identification. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
48. CaLRS: A Critical-Aware Shared LLC Request Scheduling Algorithm on GPGPU.
- Author
-
Ma, Jianliang, Meng, Jinglei, Chen, Tianzhou, and Wu, Minghui
- Subjects
GRAPHICS processing units ,PRIVATE companies ,ALGORITHMS ,BANKING industry ,MATHEMATICAL models ,COMPUTER graphics - Abstract
Ultra high thread-level parallelism in modern GPUs usually introduces numerous memory requests simultaneously. So there are always plenty of memory requests waiting at each bank of the shared LLC (L2 in this paper) and global memory. For global memory, various schedulers have already been developed to adjust the request sequence. But we find few work has ever focused on the service sequence on the shared LLC. We measured that a big number of GPU applications always queue at LLC bank for services, which provide opportunity to optimize the service order on LLC. Through adjusting the GPU memory request service order, we can improve the schedulability of SM. So we proposed a critical-aware shared LLC request scheduling algorithm (CaLRS) in this paper. The priority representative of memory request is critical for CaLRS. We use the number of memory requests that originate from the same warp but have not been serviced when they arrive at the shared LLC bank to represent the criticality of each warp. Experiments show that the proposed scheme can boost the SM schedulability effectively by promoting the scheduling priority of the memory requests with high criticality and improves the performance of GPU indirectly. [ABSTRACT FROM AUTHOR]
- Published
- 2015
- Full Text
- View/download PDF
49. Computer-Aided Color Aesthetic Evaluation Method Based on the Combination of Form and Color.
- Author
-
Kang, Wenke, Qin, Shengfeng, and Zhang, Quan
- Subjects
COLOR harmony ,COMPUTER-aided design ,AESTHETICS ,MATHEMATICAL models ,COMPUTER vision ,ALGORITHMS - Abstract
This paper presents a new method of color aesthetic evaluation based on the combination of form and color. According to the human visual physiological and psychological characteristics, this paper first proposes a new form-color field theory for the coupled form-color aesthetic evaluation based on the psychophysical field theory and the Moon and Spencer model. Second, it builds a coupled form-color topological graph for describing their interaction and develops a strength calculation algorithm for color harmony based on the new form-color field theory. Finally, it develops an aesthetic measure evaluation model for coupled form-color fields to evaluate the new theory. The experiment results show that the new coupled form-color aesthetic evaluation method is useful and can be integrated into an intelligent evaluation process for color design scheme. [ABSTRACT FROM AUTHOR]
- Published
- 2015
- Full Text
- View/download PDF
50. Data Reconstruction for a Disturbed Soil-Column Experiment Using an Optimal Perturbation Regularization Algorithm.
- Author
-
Gongsheng Li, De Yao, and Yongzai Wang
- Subjects
DATA recovery ,TRANSPORT theory ,PERTURBATION theory ,MATHEMATICAL regularization ,SOIL testing ,ALGORITHMS ,ADVECTION-diffusion equations ,MATHEMATICAL models - Abstract
This paper deals with data reconstruction problem for a real disturbed soil-column experiment using an optimal perturbation regularization algorithm. A purpose of doing the experiment is to simulate and study transport behaviors of Ca
2+ , Na+ , Mg2+ , K+ , SO4 2- , NO3 - , HCO3 - , and Cl- when they vertically penetrating through sandy soils. By data analysis to breakthrough data of the eight kinds of solute ions, two kinds of models describing their transport behaviors in the column are given. One is the advection-dispersion equation with time-dependent reaction terms suitable for three ions of HCO3 - , NO3 - , and K+ , the other is the ordinary advection-dispersion equation suitable for the rest ions. Furthermore, all the unknowns in each model are determined by utilizing the optimal perturbation regularization algorithm, respectively, and then the breakthrough data for each considered ion are reconstructed successfully. The inversion results show that the advectiondispersion model with suitable time-dependent reaction terms can be utilized to describe the experimental process and reconstruct the experimental data. [ABSTRACT FROM AUTHOR]- Published
- 2012
- Full Text
- View/download PDF
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.