442 results on '"Graphical method"'
Search Results
2. A Graphical Solution Framework for Elastoplastic Cylindrical Cavity Problem in Mohr–Coulomb Material.
- Author
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Chen, Sheng-Li
- Subjects
- *
BOUNDARY value problems , *STRAINS & stresses (Mechanics) , *EARTH pressure , *APPLIED mechanics , *COULOMB potential , *DIFFERENTIAL equations , *ANALYTICAL solutions - Abstract
Stress and deformation analysis of a cavity in an infinite/finite medium is a fundamental applied mechanics problem of interest in multiple physics and engineering disciplines. This paper develops a complete semianalytical solution for the cylindrical cavity expansion in nonassociated Mohr–Coulomb materials, by using the graphical approach and Lagrangian formulation of the cavity boundary value problem (through tracing the responses of a single material point at the cavity wall). The novelty of the new solution framework lies not only in the relaxation of the stringent intermediacy assumption for the vertical stress as usually adopted in the previous analyses, but also in the comprehensive consideration of nonhydrostatic initial stress conditions via arbitrary values of K0 (the coefficient of earth pressure at rest defined as the ratio between the horizontal and vertical initial stresses). The essence of the so-called graphical method, i.e., the unique geometrical analysis and tracking of the deviatoric stress trajectory, is fulfilled by leveraging the deformation requirement that during cavity expansion the progressive development of the radial and tangential strains must maintain to be compressive and tensile, respectively. With the incorporation of the radial equilibrium condition, the problem is formulated to solve a single first-order differential equation for the internal cavity pressure with respect to a pivotal auxiliary variable, for all the distinct scenarios of K0 being covered. Some selected results are presented for the calculated cavity pressure-expansion curve and limit cavity pressure through an example analysis. The definitive semianalytical solution proposed will be not only substantially advancing the current state of knowledge on the fundamental cavity expansion theory, but also able to serve as a unique benchmark for truly verifying the correctness and capability of the classical cornered Mohr–Coulomb constitutive model built in commercial finite element programs. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
3. Enhancing/Improving Forming Limit Curve and Fracture Height Predictions in the Single-Point Incremental Forming of Al1050 Sheet Material.
- Author
-
Hoang, Trung-Kien, Luyen, The-Thanh, and Nguyen, Duc-Toan
- Subjects
- *
MANUFACTURING defects , *YIELD curve (Finance) , *SHEET metal - Abstract
Single-point incremental forming (SPIF) has emerged as a cost-effective and rapid manufacturing method, especially suitable for small-batch production due to its minimal reliance on molds, swift production, and affordability. Nonetheless, SPIF's effectiveness is closely tied to the specific characteristics of the employed sheet materials and the intricacies of the desired shapes. Immediate experimentation with SPIF often leads to numerous product defects. Therefore, the pre-emptive use of numerical simulations to predict these defects is of paramount importance. In this study, we focus on the critical role of the forming limit curve (FLC) in SPIF simulations, specifically in anticipating product fractures. To facilitate this, we first construct the forming limit curve for Al1050 sheet material, leveraging the modified maximum force criterion (MMFC). This criterion, well-established in the field, derives FLCs based on the theory of hardening laws in sheet metal yield curves. In conjunction with the MMFC, we introduce a graphical approach that simplifies the prediction of forming limit curves at fracture (FLCF). Within the context of the SPIF method, FLCF is established through both uniaxial tensile deformation (U.T) and simultaneous uniform tensile deformation in bi-axial tensile (B.T). Subsequently, the FLCF predictions are applied in simulations and experiments focused on forming truncated cone parts. Notably, a substantial deviation in fracture height, amounting to 15.97%, is observed between simulated and experimental samples. To enhance FLCF prediction accuracy in SPIF, we propose a novel method based on simulations of truncated cone parts with variable tool radii. A FLCF is then constructed by determining major/minor strains in simulated samples. To ascertain the validity of this enhanced FLCF model, our study includes simulations and tests of truncated cone samples with varying wall angles, revealing a substantial alignment in fracture height between corresponding samples. This research contributes to the advancement of SPIF by enhancing our ability to predict and mitigate product defects, ultimately expanding the applicability of SPIF in diverse industrial contexts. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
4. A graphical solution for undrained cylindrical cavity expansion in strain-hardening frictional soil.
- Author
-
Wang, Xu, Chen, Sheng-Li, and Zhang, Jon Jincai
- Subjects
- *
DEVIATORIC stress (Engineering) , *EARTH pressure , *DIFFERENTIAL equations , *NUMERICAL integration , *SOILS - Abstract
This paper attempts to expand the graphical analysis concept proposed by Chen and Abousleiman (Géotechnique, 2022. https://doi.org/10.1680/jgeot.21.00172) to deduce the undrained expansion solution of a cylindrical cavity in shear strain-hardening Drucker–Prager frictional soil. Based on the geometrical representation of the stress state/path and strain increments in the deviatoric planes, it is shown that the deviatoric stress-Lode angle stress path can be desirably determined by solving a first-order differential equation for the stress ratio (deviatoric stress over mean effective stress) in term of the Lode angle. The essential cavity expansion curve may also be readily constructed by calculating the internal cavity pressure and the corresponding expanded cavity radius, respectively, through simple numerical integrations with respect to the same variable of stress ratio. In particular, the ultimate cavity pressure can be easily evaluated by directly integrating the expression for cavity pressure with the stress ratio up to its limiting value. Some numerical results obtained from the proposed graphical method are presented to illustrate the impacts on the cavity responses of the earth pressure coefficient at rest, K 0 , and the key plasticity hardening parameters, which have also been compared with alternative solutions that require dealing with a system of coupled differential equations involving three principal effective stress components. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
5. A graphical method-based Kharitonov theorem for robust stability analysis of incommensurate fractional-order uncertain systems.
- Author
-
Ebrahimi, Mohsen, Alaviyan Shahri, Esmat Sadat, and Alfi, Alireza
- Abstract
This paper introduces a more streamlined and convenient graphical approach to investigate the stability of fractional-order dynamical systems comprehensively. In particular, we focus on the utilization of Kharitonov theorem, renowned for robust stability analysis of incommensurate fractional-order systems in the presence of uncertainty. A novel graphical framework is illustrated, promising to streamline the stability analysis of such systems, which leads to reducing the computational burden. Using the proposed method, we can achieve the least possible Kharitonov polynomials among the existing methods to analyze the robust stability of the incommensurate fractional-order systems. To validate our approach, we perform numerical simulations on four illustrative examples, demonstrating its effectiveness. Simulation results underscore the real-world utility of our methodology, emphasizing its potential significance in fractional-order system analysis. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
6. Design and research of green concept product packaging based on artificial intelligence technology
- Author
-
Zhu Aili
- Subjects
artificial intelligence technology ,data mining ,graphical method ,green idea product ,satisfaction test ,65d17 ,Mathematics ,QA1-939 - Abstract
Through data mining, this paper completes collecting and mining information in the database using artificial intelligence. Secondly, the graphical method is analyzed, image normalization calculation is carried out to complete the technical support for green concept packaging design, and a green concept product packaging design system based on artificial intelligence technology is constructed. Finally, the ease of use experiment and user satisfaction test confirmed it. The user satisfaction test showed a satisfaction rate of 95% for response time and 97% for material recycling. The fact that other test options are above 90% indicates that the green concept product packaging design based on artificial intelligence technology is feasible.
- Published
- 2024
- Full Text
- View/download PDF
7. Use of computer programs in solving physics problems
- Author
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Ikromjonovich, Soyibnazarov Abbosjon
- Published
- 2023
- Full Text
- View/download PDF
8. A Novel Method for Estimating Time of Concentration in Ungauged Catchments
- Author
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Fathi, Abazar and Zolghadr, Masih
- Published
- 2024
- Full Text
- View/download PDF
9. Spatial-numeric method application to the movable wedge problem for Physics First pedagogy
- Author
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Sunil Dehipawala, Vazgen Shekoyan, Todd Holden, and Tak Cheung
- Subjects
movable wedge ,normal force ,graphical method ,reference frames ,Education (General) ,L7-991 ,Science ,Physics ,QC1-999 - Abstract
The objective is to solve the college physics problem of a block sliding down a movable smooth wedge without friction anywhere using a spatial-numeric perspective. The drawing method used the sum of the normal force and weight of the block to find the wedge acceleration. The drawing method results are equivalent to the algebra method results within drawing accuracy. The result of a geometric construction with regular drawing uncertainly was shown for the case without any horizontal applied force. For the case of a given horizontal applied force, an additional numeric graphing method was shown with additional drawing uncertainty in the result. The geometric construction without graphing resuted in solving the horizontal applied force case via scaling in the concept of modified gravity experienced by the block on the wedge’s slant edge, assuming a pre-requisite knowledge of algebra and trigonometry. The presented spatial numeric method and results imply a Physics First pedagogy of using the spatial numeric abilities, with the inclusion of the pre-projectile problem, pre-traffic-light problem, and post-collision problem in a one-semester syllabus.
- Published
- 2023
- Full Text
- View/download PDF
10. Statistical analysis of climate change over Hanumangarh district
- Author
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Shahid Patel and Darshan Mehta
- Subjects
graphical method ,hanumangarh district ,precipitation ,statistical method ,trend analysis ,Environmental technology. Sanitary engineering ,TD1-1066 ,Environmental sciences ,GE1-350 - Abstract
Precipitation is the most critical element of the hydrological cycle that might influence the frequency of floods or drought. Therefore, for drought and flood forecasting, knowing the precipitation pattern and its trend is mandatory. The research aims to estimate the monthly, seasonal, and annual precipitation trend using statistical (Mann Kendall test & Sen's Slope estimator) and graphical (Innovative Trend Analysis method) for the Hanumangarh district of N-E Rajasthan. The mean monthly precipitation data were gathered from the India-WRIS from 1901 to 2022 (122 years). Seasonal and annual precipitation trend variations were examined by statistical methods and compared with the graphical method. The study results conclude that precipitation trends showed variability for the SW monsoon season from the graphical to the statistical method. For the SW monsoon season, the decreasing trend was seen using statistical methods. In contrast, the graphical method revealed an increasing trend. During the annual precipitation, increasing trends were seen using statistical and graphical methods. It is found that the ITA method is more efficient in finding trends because it does not assume any assumptions like that of the MK test. This study will help water resources engineers and local people with sustainable management, planning, and development of water resources in the Hanumangarh district. HIGHLIGHTS Trends in seasonal and annual precipitation time series are assessed using both statistical and graphical methods and then results are compared.; The results of the statistical method are well-matched with the graphical method.; The ITA method is easier to apply for finding trends.; The ITA method is more accurate because it does not consider any assumptions.;
- Published
- 2023
- Full Text
- View/download PDF
11. Estimation of the Parameters of the Modified Weibull Distribution with Bathtub-shaped Failure Rate Function.
- Author
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Hussein Adam, Adam Abdelrahman and Sazak, Hakan SavaÅŸ
- Subjects
- *
WEIBULL distribution , *PARAMETER estimation , *SOFTWARE reliability , *HAZARD function (Statistics) - Abstract
In this study, we propose two estimators called the 3-step modified maximum likelihood (MML) and the combined estimators of the parameters of the modified Weibull distribution which is used in reliability models with bathtub-shaped failure rate function. The simulations show the superiority of both estimators over the graphical estimators. Particularly, the combined estimators are the better of the two. Two real-life data applications also show the superiority of the proposed estimators compared to the graphical estimators. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
12. Estimation of error in four-bar mechanism under dimensional deviations.
- Author
-
Jaiswal, Ankur and Jawale, H. P.
- Abstract
A four-bar mechanism is a basic kinematic chain in most of planar mechanisms. Four-bar chains are synthesized for a specific task. The output deviates from the desired one due to many reasons broadly from the group of systematic and random input sources. The work presented herewith deals with the error estimation in the four-bar path generation mechanism under link tolerance. The primary estimation of error is carried out using a Taylor series approximation with a modified error equation. The inaccuracy is estimated using sample independent variables. A geometrical method for the estimation of specific errors is developed. The results are verified using the CAD model. The appropriateness of the Taylor series approximation with modified error equation estimations is compared with exact solutions from the geometrical method. The methodology is demonstrated through a sample case of the four-bar mechanism presented to compare the capability of the two methods. The deviations due to single systematic inaccuracy are exposed, and one of the methods- i.e. the geometrical method is found to be the robust method of error evaluation. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
13. Graphical modeling of discontinuous stress field for RC deep beams under uniform load.
- Author
-
Liu, Zhao and Lei, Haipeng
- Subjects
- *
CONCRETE beams , *STRUT & tie models , *BANDWIDTHS - Abstract
The fanning compression stress pattern in RC deep beams under uniform load presents a challenge to formulating the configuration of strut‐and‐tie model (STM). To this end, this paper proposes an alternative method for creating a graphical discontinuous stress field model (DSFM) to fill up the whole beam continuum. It comprises a certain number of trapezoidal stress‐bands with varying bandwidths, and their stress values can be calculated based on force equilibrium conditions. Several stress subfields are defined through a certain stress combination from several directions. The DSFM is implementable for both service limit state (SLS) and ultimate limit state (ULS) in that its configuration is primarily oriented by elastic stress field and only a limited plastic redistribution is allowed for plastic failure. The graphical procedure of DSFM is demonstrated and examined by a test deep beam example, which shows that the predictions are fairly in good agreement with the test results. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
14. Determination of scattering and Urbach absorption contributions to the light extinction in PTFE films by using graphical representation technique and numerical solution of the inverse problem.
- Author
-
Sopinskyy, M. V., Grytsenko, K. P., Villringer, C., Kolomzarov, Yu. V., and Schrader, S.
- Subjects
- *
LIGHT absorption , *INVERSE problems , *ABSORPTION coefficients , *RAYLEIGH scattering , *ATTENUATION coefficients , *LIGHT scattering - Abstract
Ellipsometrically obtained spectral dependences of ordinary αxy and extra-ordinary αz extinction/attenuation coefficients within the spectral range λ = 300…980 nm of uniaxially anisotropic polytetrafluoroethylene (PTFE) films were analyzed. We considered the capabilities and specific features of the graphical representation technique for determining the contribution of Rayleigh scattering and Urbach absorption to light attenuation in the spectral range beyond fundamental absorption. It has been shown that the graphical approach enables to estimate these contributions qualitatively, semi-quantitatively or quantitatively, depending on the situation. The conclusions made using the analysis of graphical representation are confirmed by numerical solution of the inverse problem via simulation of the αxy (λ), αz (λ) experimental dependences within the framework of a best-fit procedure. Being based on both of these approaches, we have ascertained that, in the as-prepared PTFE films, the so-called anomalous light scattering (ALS) with the spectral dependence of scattering coefficient αs ≈ as λ–p (p > 4) takes place. Transformation of scattering from ALS to the Rayleigh one with p ≅ 4 due to annealing is accompanied by an increase of Urbach (subband) absorption. Both of these factors cause narrowing the dynamic range of extinction coefficient values. Both scattering and absorption coefficients are higher for the component of light polarized along the normal to the substrate as compared to the component polarized in parallel to it. The relationship between observed behavior of the scattering and absorption coefficients and the film structure has been discussed. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
15. Bayesian estimation versus maximum likelihood estimation in the Weibull-power law process.
- Author
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Jokiel-Rokita, Alicja and Magiera, Ryszard
- Subjects
- *
MAXIMUM likelihood statistics , *BAYES' estimation , *ENGINEERING reliability theory - Abstract
The Bayesian approach is applied to estimation of the Weibull-power law process (WPLP) parameters as an alternative to the maximum likelihood (ML) method in the case when the number of events is small. For the process model considered we propose to apply the independent Jeffreys prior distribution and we argue that this is a useful choice. Comparisons were also made between the accuracy of the estimators obtained and those obtained by using other priors—informative and weakly informative. The investigations show that the Bayesian approach in many cases of a fairly broad collection of WPLP models can lead to the Bayes estimators that are more accurate than the corresponding ML ones, when the number of events is small. The problem of fitting the WPLP models, based on ML and Bayes estimators, to some real data is also considered. It is shown that the TTT-concept, used in the reliability theory, is not fully useful for the WPLP models, and it may be so for some other trend-renewal processes. In order to assess the accuracy of the fitting to the real data considered, two other graphical methods are introduced. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
16. Armature Reaction Analysis and Performance Optimization of Hybrid Excitation Starter Generator for Electric Vehicle Range Extender.
- Author
-
Gao, Mingling, Ren, Jinling, Hu, Wenjing, Han, Yutong, Geng, Huihui, Yan, Shilong, and Xu, Mingjun
- Subjects
ELECTRIC generators ,ARMATURES ,HYBRID electric vehicles ,ELECTRIC vehicles ,PERMANENT magnets ,MAGNETIC fields - Abstract
The armature reaction of the hybrid excitation starter generator (HESG) under load conditions will affect the distribution of the main magnetic field and the output performance. However, using the conventional field-circuit combination method to study the armature reaction has the problem of low accuracy and inaccurate influencing factors. Therefore, this paper proposed a graphical method to analyze the armature reaction and a new type of HESG with a combined-pole permanent magnet (PM) rotor and claw-pole electromagnetic rotor. The analytical formula of the voltage regulation rate under the armature reaction was derived using the graphical method. The main influencing parameters of the armature reaction magnetic field (ARMF) were analyzed, and the overall output performance was analyzed using finite element software. On this basis, comparison analyses before and after optimization and the prototype test were carried out. The results show that the direct-axis armature reaction reactance, quadrature-axis armature reaction reactance, and voltage regulation rate of the optimized HESG were significantly reduced, the output voltage range of the whole machine was wide, and the voltage regulation performance was good. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
17. A graphical method of presenting property rights, building types, and residential behaviors: A case study of Xiaoxihu historic area, Nanjing
- Author
-
Yinan Dong, Dongqing Han, and Marco Trisciuoglio
- Subjects
Property rights ,Building types ,Residential behaviors ,Graphical method ,Historic area ,Architecture ,NA1-9428 - Abstract
One of the main reasons for the decline of urban historic areas in China is the co-existence of multiple property rights. It also deeply affects conservation and regeneration practice. This paper aims to propose a graphical method that illustrates the association between property rights, space, and resident behavior. Based on typological maps and justified graphs, a three-step method was proposed to visualize the relationships between these three elements. The final graph and quantitative data were used to observe the evolution of the courtyard building from a diachronic perspective, as well as to compare the residential behavior in different types from a synchronic perspective. The results show that following the subdivision of property rights, the building layout become more diverse due to various illegal additions, while the residential behavior within different building types tends to be consistent. Moreover, the study observed the traditional Chinese courtyard buildings’ adaptability. The findings contribute to understand the evolution of Chinese urban historic areas and internal motivation, and provide guidance for the conservation and regeneration practice.
- Published
- 2022
- Full Text
- View/download PDF
18. Application of innovative trend analysis on rainfall time series over Rajsamand district of Rajasthan state
- Author
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Jinal Pastagia and Darshan Mehta
- Subjects
climate change ,graphical method ,hydrological cycle ,innovative trend analysis ,long-term trend ,Water supply for domestic and industrial purposes ,TD201-500 ,River, lake, and water-supply engineering (General) ,TC401-506 - Abstract
Rainfall is an important part of the hydrological cycle, as well as its variability, and is relevant to drought and floods. Long-term changes in hydrological processes are referred to as climate change for an area. Urbanization, population growth, and economic growth are all having negative effects on the environment. The study of trends in the long term is essential from climatic change and socioeconomic perspectives. Examining the temporal variations in rainfall is crucial because changes in rainfall patterns and distribution can have a significant impact on the amount of water available in a watershed. The objective of the study is to assess the long-term (1902–2021) temporal trends in seasonal (winter, pre-monsoon, monsoon, and post-monsoon) and annual rainfall for the Rajsamand district of Rajasthan state using the innovative trend analysis (ITA) technique. Due to its ability to provide results in graphical form, the ITA approach is a very useful tool for detecting patterns in rainfall time series data. This technique is also used to detect trends as ‘low,’ ‘medium,’ and ‘high,’ which should be considered in future studies on floods ‘high’ and drought ‘low’, respectively. Based on the above study, it is observed that no trend is detected for the annual season, a positive trend is detected in the winter season and a negative trend is detected for pre-monsoon and post-monsoon seasons in some regimes respectively. The ITA of the S-W monsoon also specifies that in the low regime the nature of the trend is increasing and in the high regime nature of the trend is decreasing. This research will serve as a scientific foundation for assessing and mitigating the effect of climate change on the environment to reduce the risk of weather patterns. HIGHLIGHTS The innovative trend analysis (ITA) method is used in the study.; To apply the ITA approach to examine the annual and seasonal patterns of various precipitation intensities in Rajsamand.; To discuss the patterns of seasonal and annual rainfall variability across the region.; ITA method is a very useful tool for detecting patterns in rainfall time series.; ITA method is both simple and effective.;
- Published
- 2022
- Full Text
- View/download PDF
19. Alternative Models for Evaluating Convertible Bond: Review and Integration
- Author
-
Lee, Cheng-Few, Kao, Lie-Jane, Wu, Po-Cheng, Lee, Cheng-Few, editor, and Lee, Alice C., editor
- Published
- 2022
- Full Text
- View/download PDF
20. Enhancing/Improving Forming Limit Curve and Fracture Height Predictions in the Single-Point Incremental Forming of Al1050 Sheet Material
- Author
-
Trung-Kien Hoang, The-Thanh Luyen, and Duc-Toan Nguyen
- Subjects
SPIF (single-point incremental forming) ,forming limit curve at fracture (FLCF) ,forming limit curve at necking (FLCN) ,modified maximum force criterion (MMFC) ,graphical method ,sheet material Al1050 ,Technology ,Electrical engineering. Electronics. Nuclear engineering ,TK1-9971 ,Engineering (General). Civil engineering (General) ,TA1-2040 ,Microscopy ,QH201-278.5 ,Descriptive and experimental mechanics ,QC120-168.85 - Abstract
Single-point incremental forming (SPIF) has emerged as a cost-effective and rapid manufacturing method, especially suitable for small-batch production due to its minimal reliance on molds, swift production, and affordability. Nonetheless, SPIF’s effectiveness is closely tied to the specific characteristics of the employed sheet materials and the intricacies of the desired shapes. Immediate experimentation with SPIF often leads to numerous product defects. Therefore, the pre-emptive use of numerical simulations to predict these defects is of paramount importance. In this study, we focus on the critical role of the forming limit curve (FLC) in SPIF simulations, specifically in anticipating product fractures. To facilitate this, we first construct the forming limit curve for Al1050 sheet material, leveraging the modified maximum force criterion (MMFC). This criterion, well-established in the field, derives FLCs based on the theory of hardening laws in sheet metal yield curves. In conjunction with the MMFC, we introduce a graphical approach that simplifies the prediction of forming limit curves at fracture (FLCF). Within the context of the SPIF method, FLCF is established through both uniaxial tensile deformation (U.T) and simultaneous uniform tensile deformation in bi-axial tensile (B.T). Subsequently, the FLCF predictions are applied in simulations and experiments focused on forming truncated cone parts. Notably, a substantial deviation in fracture height, amounting to 15.97%, is observed between simulated and experimental samples. To enhance FLCF prediction accuracy in SPIF, we propose a novel method based on simulations of truncated cone parts with variable tool radii. A FLCF is then constructed by determining major/minor strains in simulated samples. To ascertain the validity of this enhanced FLCF model, our study includes simulations and tests of truncated cone samples with varying wall angles, revealing a substantial alignment in fracture height between corresponding samples. This research contributes to the advancement of SPIF by enhancing our ability to predict and mitigate product defects, ultimately expanding the applicability of SPIF in diverse industrial contexts.
- Published
- 2023
- Full Text
- View/download PDF
21. Armature Reaction Analysis and Performance Optimization of Hybrid Excitation Starter Generator for Electric Vehicle Range Extender
- Author
-
Mingling Gao, Jinling Ren, Wenjing Hu, Yutong Han, Huihui Geng, Shilong Yan, and Mingjun Xu
- Subjects
armature reaction ,voltage regulation rate ,graphical method ,hybrid excitation starter generator ,extended-range electric vehicle ,Electrical engineering. Electronics. Nuclear engineering ,TK1-9971 ,Transportation engineering ,TA1001-1280 - Abstract
The armature reaction of the hybrid excitation starter generator (HESG) under load conditions will affect the distribution of the main magnetic field and the output performance. However, using the conventional field-circuit combination method to study the armature reaction has the problem of low accuracy and inaccurate influencing factors. Therefore, this paper proposed a graphical method to analyze the armature reaction and a new type of HESG with a combined-pole permanent magnet (PM) rotor and claw-pole electromagnetic rotor. The analytical formula of the voltage regulation rate under the armature reaction was derived using the graphical method. The main influencing parameters of the armature reaction magnetic field (ARMF) were analyzed, and the overall output performance was analyzed using finite element software. On this basis, comparison analyses before and after optimization and the prototype test were carried out. The results show that the direct-axis armature reaction reactance, quadrature-axis armature reaction reactance, and voltage regulation rate of the optimized HESG were significantly reduced, the output voltage range of the whole machine was wide, and the voltage regulation performance was good.
- Published
- 2023
- Full Text
- View/download PDF
22. Graphical optimization method for bidirectional corridor progression under the signal design mode of split phasing.
- Author
-
Jiang, Shu-yan, Lu, Kai, Zhao, Yi-ming, Huang, Zi-hao, Deng, Yuan-hao, and Jing, Bin-bin
- Abstract
Copyright of Journal of Central South University is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2023
- Full Text
- View/download PDF
23. A simulation and experimental study on the deep drawing process of SPCC sheet using the graphical method
- Author
-
The-Thanh Luyen, Van-Canh Tong, and Duc-Toan Nguyen
- Subjects
Forming limit curve (FLC) ,Finite element model ,Modified maximum force criterion (MMFC) ,Graphical method ,Deep drawing ,Cylindrical cup ,Engineering (General). Civil engineering (General) ,TA1-2040 - Abstract
This study presents a method for finite element (FE) simulation of a deep drawing process of a cold-rolled carbon steel (SPCC) sheet material based on the graphical method. First, uniaxial tensile specimens were prepared and experimental tests were conducted to determine the flow stress curves. The calculation of the fracture points at special strain modes (plane strain, uniaxial tensile strain, and biaxial tensile strain) was presented using the modified maximum force criterion (MMFC). After that, the graphical method was adopted for the estimation of the forming limit curve (FLC) based on several hardening laws. FE models for a deep drawing process of the SPCC sheet were then built using the calculated FLCs. Using FE simulations, the fracture heights of cylinder cups formed by the deep drawing process were finally determined and compared with those from experiments. The results showed a good agreement between simulated and measured fracture height with a maximum of 3.6 % deviation. Additionally, simulations and corresponding experiments were performed to investigate the effects of the blank holder force, punch corner radius, and drawing ratio on the fracture height of cylinder cups.
- Published
- 2022
- Full Text
- View/download PDF
24. Improvement of the Graphical Method for Plotting the Shear and Moment Diagrams for Members Subjected to Linearly Varying Loads
- Author
-
Muhammed Abbas Husain and Abdulkhaliq Salim Ali
- Subjects
shear diagrams ,moment diagram ,graphical method ,improvement ,varying loads ,Mechanical engineering and machinery ,TJ1-1570 - Abstract
This study presents an improvement of the graphical method for plotting the shear and moment diagrams for the structural members under linearly varying loads (triangular and trapezoidal loads). Based on the parabolic nature of the shear function, when the loading varies linearly, and on the relations among load, shear, and moment, a mathematical equation is developed to locate the zero-shear point, while a geometric technique is presented to calculate the parabolic shear area. Five comprehensive examples of beams loaded with linearly varying loads are selected to illustrate the steps of the solution for the proposed techniques. The results demonstrated the applicability of the presented method, and gave exact diagrams compared with the basic graphical method. It is concluded that the proposed improved method is generally more convenient, less time-consuming, and has less computational efforts because it does not require sectioning, solving equilibrium equations, and quadratic formulas compared with the basic graphical method.
- Published
- 2022
- Full Text
- View/download PDF
25. A Comparison Study by Simulation/Experiment to Verify the Effect of Predicted Forming Limit Diagram Based on Graphical Method at Elevated Temperature for SPCC Sheet Material
- Author
-
The-Thanh, Luyen, Thi-Bich, Mac, Tien-Long, Banh, Duc-Toan, Nguyen, Ghosh, Arindam, Series Editor, Chua, Daniel, Series Editor, de Souza, Flavio Leandro, Series Editor, Aktas, Oral Cenk, Series Editor, Han, Yafang, Series Editor, Gong, Jianghong, Series Editor, Jawaid, Mohammad, Series Editor, Parinov, Ivan A., editor, Chang, Shun-Hsyung, editor, Kim, Yun-Hae, editor, and Noda, Nao-Aki, editor
- Published
- 2021
- Full Text
- View/download PDF
26. Linear Programming and Dynamic Programming
- Author
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Balaji, C. and Balaji, C.
- Published
- 2021
- Full Text
- View/download PDF
27. PROPOSAL OF A NEW GRAPHICAL METHOD FOR SOLVING THE NEWSVENDOR PROBLEM WITH RANDOM YIELDS.
- Author
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GUEZZEN, Amine Hakim and Zaki, Sari
- Subjects
NEWSVENDOR model ,PROBLEM solving - Abstract
The newsvendor model is widely used in production systems to determine the optimal quantity of products to be produced in the presence of random demand. In addition, in industrial production, many modern processes and services are significantly affected by random yield. This paper begins by describing the general background of the random demand and random yield newsvendor model. Next, we summarize the mathematical formulation. Then, we present our approach and the proposed graphical solution technique. [ABSTRACT FROM AUTHOR]
- Published
- 2023
28. UNCERTAINTY OF A CRITICAL POINT ON THE FREEZING CURVE.
- Author
-
İbrahimoğlu, Beycan
- Subjects
CRITICAL point (Thermodynamics) ,PHYSICAL laws ,CRITICAL analysis ,BENZENE - Abstract
P. W. Bridgman developed a method to measure the force acting on a moving piston of known area and conducted experiments on gases, liquids and solids at high pressures. He reported that there is no critical point on the freezing curve in his experiments on various materials. Researchers working in universities and laboratories in the USA, France, England, Germany, Russia, the Netherlands and other universities and laboratories have reported that there is no critical point on the melting curve at high pressures in their experiments on gases, liquids and solids with this method developed by P. W. Bridgman. The main method of research in physical chemistry is experience. The new physical chemistry is an experimental science. A real physicochemical experiment is of great importance in the study of physical laws and processes. The method and methodology applied in determining the hypothesis put forward is the most important factor. Experiments are key to propose a hypothesis and solve a problem. Although the existence of a critical point on the melting curve seems theoretically and graphically possible, P. W. Bridgman and other researchers have reported that there is no critical point. In our opinion, it is not possible to determine the existence of a critical point on the freezing curve by the method applied by P. W. Bridgman and other researchers in their experiments. With this method it was possible to determine the pressure and temperature dependent melting curve. For nearly a century, the presence or absence of a critical point on the freezing curve has been a matter of debate. In the experiments conducted by P. W. Bridgman and other researchers, it was found that there was no critical point, but it is possible to determine the existence of a critical point by the experimental results of the intermittent metastable state on the freezing curve at high pressures or by applying the geometric method depending on the thermodynamic parameters of the substance. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
29. A conceptual efficient design of energy recovery systems using a new energy-area key parameter
- Author
-
Ibrahim H. Alhajri, Mamdouh A. Gadalla, and Hany A. Elazab
- Subjects
Pinch analysis ,Graphical method ,Energy-area parameter ,HEN ,Heat integration ,Dimethyl ether ,Electrical engineering. Electronics. Nuclear engineering ,TK1-9971 - Abstract
Energy integration in petrochemical and refining industries is an effective concept to minimize dependence on heating and cooling utilities through networks of exchanger equipment. Pinch Analysis is very popular and successful technique to optimize heat recovery between heat sources and sinks. Yet, design of networks of exchangers is challenging and requires careful attention to energy consumption and exchanger areas. This work presents a graphical methodology to design exchanger networks taking into account both heat loads and transfer areas of exchanger units in one single information. A new parameter is introduced for design that is the ratio between the heat load and the exchanger area, and is determined in kW/m2. It is defined as an energy-area parameter expressing how much heat the exchanger would transfer per every meter square of area. Such parameter will be valuable key in design to screen matches of exchangers providing that both the heat and area are considered. The higher the value of the parameter, the better the performance of the exchanger, i.e. maximum heat transfer rate for minimum exchanger area. The design methodology embedding the energy-area parameter guarantees HEN designs with energy targets and minimum areas. A case is studied for the production of 100,000 t/y of dimethyl ether. An optimum network is generated by applying the new parameter with less exchanger areas and hot utility of 25% and 30%, respectively compared with an automated design by Aspen Energy Analyzer®. Also, substantial savings of about 47% in the total cost of the network are earned.
- Published
- 2021
- Full Text
- View/download PDF
30. Revisiting undrained cavity expansion problem in critical state soils: A simple graph‐based approach.
- Author
-
Wang, Xu and Chen, Shengli
- Subjects
- *
SOILS , *NUMERICAL integration , *ANALYTICAL solutions , *DIFFERENTIAL equations , *CLAY - Abstract
This paper presents analytical solutions for the finite expansion problems of a spherical or cylindrical cavity, using a simple yet novel graphical approach recently proposed by Chen & Abousleiman in 2022, in both original Cam Clay (OCC) and modified Cam Clay (MCC) soils under undrained conditions. It is shown that, for a soil mass subjected to isotropic in situ stress conditions, the stress paths in the deviatoric plane for the spherical and cylindrical cavity expansions turn out to be two straight lines, which correspond to Lode angles equal to 11π6$\frac{{11\pi }}{6}$ and 5π3$\frac{{5\pi }}{3}$, respectively. The desired limiting cavity pressure therefore can be directly and accurately evaluated through simple numerical integration with respect to the mean effective stress, while the relationship between the internal cavity pressure and the cavity radius, the cavity expansion curve, may be equally conveniently determined. Numerical results obtained from the current graphical method, for a range of the values of over consolidation ratio considered, compare extremely well with those from the conventional semianalytical formulations of the undrained cavity problem that involve solving a system of coupled governing differential equations. It is interesting to note that the representative and approximate solution developed by Collins & Yu in 1996 indeed is a correct one for the spherical cavity expansion problem, and, with minor modifications, will be applicable for the accurate calculation of the responses of the cylindrical cavity as well. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
31. Study on Cyclic Pile Load Test of Pile Socketed in Rock
- Author
-
Sumisha, A. P., Johnson, Arvee Sujil, di Prisco, Marco, Series Editor, Chen, Sheng-Hong, Series Editor, Vayas, Ioannis, Series Editor, Kumar Shukla, Sanjay, Series Editor, Sharma, Anuj, Series Editor, Kumar, Nagesh, Series Editor, Wang, Chien Ming, Series Editor, Latha Gali, Madhavi, editor, and Raghuveer Rao, P., editor
- Published
- 2020
- Full Text
- View/download PDF
32. A graphical method of presenting property rights, building types, and residential behaviors: A case study of Xiaoxihu historic area, Nanjing.
- Author
-
Dong, Yinan, Han, Dongqing, and Trisciuoglio, Marco
- Abstract
One of the main reasons for the decline of urban historic areas in China is the co-existence of multiple property rights. It also deeply affects conservation and regeneration practice. This paper aims to propose a graphical method that illustrates the association between property rights, space, and resident behavior. Based on typological maps and justified graphs, a three-step method was proposed to visualize the relationships between these three elements. The final graph and quantitative data were used to observe the evolution of the courtyard building from a diachronic perspective, as well as to compare the residential behavior in different types from a synchronic perspective. The results show that following the subdivision of property rights, the building layout become more diverse due to various illegal additions, while the residential behavior within different building types tends to be consistent. Moreover, the study observed the traditional Chinese courtyard buildings' adaptability. The findings contribute to understand the evolution of Chinese urban historic areas and internal motivation, and provide guidance for the conservation and regeneration practice. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
33. A graphical approach for the determination of outrigger loads in mobile cranes.
- Author
-
Romanello, Giuseppe
- Subjects
- *
MOBILE cranes , *CRANES (Machinery) , *CENTER of mass , *RIGID bodies , *NUMBER systems - Abstract
In the present work, a new method for the determination of the outrigger loads in mobile cranes is proposed. The approach adopted assumes the mobile crane as a rigid body and the ground having a linear elastic behavior. The outrigger reactions are determined, using the concept of complete support pattern, through the calculation of the area of triangles constructed within it. The main feature of the method is that the determination of the outrigger reactions can be done by means of graphical considerations with the advantage to perform the task quickly and without the use of complicated calculations. The knowledge of the outrigger pattern, the resultant of all the forces applied and the center of mass of the system crane-payload are only needed as input data. Although the method is suitable for cranes with an outrigger system of any number and shape, the simplification deriving from the use of the graphical approach is fully available only for an outrigger system with four outriggers having a specific shape. These configurations, however, represent the most common configuration found in real applications. The validity of the method proposed has been proven comparing the results with data available in the cranes' manuals and with actual reactions of the outriggers of a mobile cranes operating on site. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
34. Faz diyagramında plazmanın konumu.
- Author
-
İbrahimoğlu, Beycan, Yılmazoğlu, Mustafa Zeki, and Karakaya, Fuat
- Subjects
- *
PHASE diagrams , *PHASE transitions , *PHASE equilibrium , *PHASES of matter , *CRITICAL point (Thermodynamics) - Abstract
The study of phase transitions and critical parameters has a history of nearly one century. The interest shown in this field of science has provided an accumulation of knowledge about phase transitions and critical states of matter through significant researches. On the other hand, theoretical and experimental studies still show that the pressure and temperature diagram of the material is not completed. In particular, the absence of plasma in the (p-T) phase diagram, the uncertainty of the pressure-dependent boundary range of the liquid phase and the state of the equilibrium curves are the focus of the studies. In the phase diagram of pure substance (p-T), the representation of only three phases and the boundary curves separating these phases with two basic points limits the phase diagram. However, as long as the plasma, which constitutes 98% of the universe and is accepted as the fourth phase of matter, does not take place in the phase diagram (p-T) and the liquid phase remains uncertain, phase transitions and critical parameters cannot be fully resolved. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
35. A Graphical Method for Fire Design of Reinforced Concrete Beams.
- Author
-
Albuquerque, Gabriela B. M. L., Silva, Valdir P., and Rodrigues, João Paulo C.
- Subjects
- *
CONCRETE beams , *FINITE element method , *BENDING moment - Abstract
Reinforced concrete beams lose resistance at high temperatures and so as to guarantee their good performance, it is mandatory to consider this accidental action in design. As an alternative to the methods proposed by the European and Brazilian standards, above all the tabular method that, despite its simple application, limits calculations to a few pre-defined values, a new tool for fire design of these beams is proposed herein. A graphical method was developed with the Temperature Calculation and Design (TCD) software, which performs transient bi-dimensional thermo-structural analysis using the finite element method. The main variable of this method consists of the resistance to the bending moment of a heated cross-section. For its validation, the moment of four rectangular sections was determined according to four simplified methods. These results were compared among themselves and to those obtained by a more advanced method. They were all verified to lead to similar results. With regard to the TCD, whose results were used for the preparation of the graphical method, the maximum difference compared to a more advanced method was approximately 2.5%. After validation, graphs that associate the ratio between the applied moment in fire and the resistance to bending moment at ambient temperature to the fire resistance for different beams were created. These graphs present design solutions for more than 2300 beam models with T-shaped cross-sections in assorted lengths, heights, covers and reinforcement arrangements, both positive and negative. In the application examples, the results from the graphical method were generally more economic when compared to the tabular method of the fire design standards. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
36. The Geometry of Timber Lamella Vaults: Prototype Analysis.
- Author
-
Petrović, Milica, Ilić, Isidora, Mijatović, Svetislav, and Šekularac, Nenad
- Subjects
PROTOTYPE design & construction ,GEOMETRICAL constructions ,TIMBER ,GEOMETRY ,PROTOTYPES ,BLOCK designs - Abstract
This paper presents timber lamella structures applied to the circular cylinder surface when all lamellae axes intersect at the nodes. To achieve the uniformity of all elements in this structure, the geometry of the structure must be carefully designed. The main methods for the research are graphical and numerical methods for geometric design and a prototype construction for a specific geometric pattern. The methods are discussed for their ease of replication, as well as the possibility of reinterpretation on other surfaces, while the prototype design and construction give insight into the process from design to execution. The combination of these methods allows for a thorough analysis of the geometry for lamella structures. The analysis shows that geometrical design must begin from the whole to the lamella, and that the number of element types in the structure depends on the disposition of the elements and the angle of the pattern. The discussion shows the advantages and limitations of the proposed methods, while the conclusions give the guidelines for the implementation of lamella structures into new design projects. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
37. Assessment of genotype‐trait interaction in maize (Zea mays L.) hybrids using GGT biplot analysis
- Author
-
Seyed Habib Shojaei, Khodadad Mostafavi, Mahmoud Khosroshahli, Mohammad Reza Bihamta, and Hossein Ramshini
- Subjects
corn ,correlation coefficient ,genotype–trait interaction ,graphical method ,PCA ,Nutrition. Foods and food supply ,TX341-641 - Abstract
Abstract In order to investigate the interaction of genotype × trait and relationships among agronomic traits on 12 maize hybrids, an experiment was conducted in a randomized complete block design (RCBD) with three replicates in four regions of Karaj, Birjand, Shiraz, and Arak. Results of analysis of variance indicated that most of the genotypes were significantly different in terms of agronomic traits. Mean comparison by Duncan's method showed that KSC705 genotype was more favorable than other genotypes in all studied regions. SC604 genotype in Birjand and Karaj regions and KSC707 genotype in Shiraz region have higher rank than other genotypes. Correlation analysis was used to investigate the relationships between traits. In most of the studied regions, traits of number of grains in row and number of rows per ear were positively and significantly correlated with grain width and grain weight with grain yield. Graphical analysis was used to further investigate. Genotypes–trait interaction graph explained 59.27%, 61.22%, 59.17%, and 61.95% of total variance in Karaj, Birjand, Shiraz, and Arak, respectively. Based on the multivariate graph, KSC705, KSC706, and SC647 genotypes were identified as superior genotypes in all studied regions and KSC400 genotype did not show much response to change in traits. Correlation between grain width and number of rows in ear, plant height and grain length, one thousand grain weight and grain thickness, and ear diameter with number of grains in row was positive and significant. The results of classification graph of genotypes also divided the cultivars in to three groups as follows: KSC703, KSC400, and KSC706 genotypes in the first group; DC370, SC604, and SC301 in the second group; and KSC260, KSC704, KSC707, and SC301 in the third group.
- Published
- 2020
- Full Text
- View/download PDF
38. The Geometry of Timber Lamella Vaults: Prototype Analysis
- Author
-
Milica Petrović, Isidora Ilić, Svetislav Mijatović, and Nenad Šekularac
- Subjects
right circular cylinder ,parametric equations ,graphical method ,timber structures ,Building construction ,TH1-9745 - Abstract
This paper presents timber lamella structures applied to the circular cylinder surface when all lamellae axes intersect at the nodes. To achieve the uniformity of all elements in this structure, the geometry of the structure must be carefully designed. The main methods for the research are graphical and numerical methods for geometric design and a prototype construction for a specific geometric pattern. The methods are discussed for their ease of replication, as well as the possibility of reinterpretation on other surfaces, while the prototype design and construction give insight into the process from design to execution. The combination of these methods allows for a thorough analysis of the geometry for lamella structures. The analysis shows that geometrical design must begin from the whole to the lamella, and that the number of element types in the structure depends on the disposition of the elements and the angle of the pattern. The discussion shows the advantages and limitations of the proposed methods, while the conclusions give the guidelines for the implementation of lamella structures into new design projects.
- Published
- 2022
- Full Text
- View/download PDF
39. The Application of Heuristic Teaching Method in Explaining the Asterisk Triangles Pattern in C Language
- Author
-
Wu, Xiaoqiang, Hao, Ruican, Cheng, Hongfang, Akan, Ozgur, Editorial Board Member, Bellavista, Paolo, Editorial Board Member, Cao, Jiannong, Editorial Board Member, Coulson, Geoffrey, Editorial Board Member, Dressler, Falko, Editorial Board Member, Ferrari, Domenico, Editorial Board Member, Gerla, Mario, Editorial Board Member, Kobayashi, Hisashi, Editorial Board Member, Palazzo, Sergio, Editorial Board Member, Sahni, Sartaj, Editorial Board Member, Shen, Xuemin (Sherman), Editorial Board Member, Stan, Mircea, Editorial Board Member, Jia, Xiaohua, Editorial Board Member, Zomaya, Albert Y., Editorial Board Member, Sun, Guanglu, editor, Gan, Jianhou, editor, Liu, Shuai, editor, Lang, Fei, editor, and Lu, Zeguang, editor
- Published
- 2019
- Full Text
- View/download PDF
40. New methods for multiple testing in permutation inference for the general linear model.
- Author
-
Mrkvička, Tomáš, Myllymäki, Mari, Kuronen, Mikko, and Narisetty, Naveen Naidu
- Subjects
- *
PERMUTATIONS , *TEST methods , *BRAIN imaging , *STATISTICAL hypothesis testing - Abstract
Permutation methods are commonly used to test the significance of regressors of interest in general linear models (GLMs) for functional (image) data sets, in particular for neuroimaging applications as they rely on mild assumptions. Permutation inference for GLMs typically consists of three parts: choosing a relevant test statistic, computing pointwise permutation tests, and applying a multiple testing correction. We propose new multiple testing methods as an alternative to the commonly used maximum value of test statistics across the image. The new methods improve power and robustness against inhomogeneity of the test statistic across its domain. The methods rely on sorting the permuted functional test statistics based on pointwise rank measures; still, they can be implemented even for large data. The performance of the methods is demonstrated through a designed simulation experiment and an example of brain imaging data. We developed the R package GET, which can be used for the computation of the proposed procedures. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
41. Comparison of the Performance of the Methods Used to Find the Weibull Parameters at Different Heights.
- Author
-
Kaplan, Yusuf Alper
- Subjects
- *
WEIBULL distribution , *MAXIMUM likelihood statistics , *WIND speed , *MOMENTS method (Statistics) , *STATISTICAL errors - Abstract
In this study, the coefficients of Weibull Distribution Function (WDF) were calculated at two different heights using by six different methods. One-year wind data were used to determine the coefficients of WDF at different heights, and the wind data were obtained from a metrology station with a height of 10 m and a real wind turbine with a height of 80 m in Turkey's Hatay region. The used methods in this study were Graphical Method (GM), Empirical Method, Energy Pattern Method (EPM), Energy Trend Method, Maximum Likelihood Method and Moment Method.\ Three different statistical error analysis tests were used to compare the performance of the used methods at two different heights. Estimated mean wind speed and power values are the most important indicators to evaluate the performance of the used methods. In this study, mean wind speeds and powers were estimated in all methods for both heights using the WDF. These obtained values were compared with the actual real data and the best performing method was determined at both different heights for selected region. When the results were evaluated in general at both different heights, it was seen that the best performance method was the EPM and the worst performance method was the GM. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
42. A new approach based on moving least square method for calculating the Weibull coefficients.
- Subjects
LEAST squares ,WEIBULL distribution ,STANDARD deviations ,WIND speed ,WIND power - Abstract
In this study, the graphical method, which is widely used to find the coefficients of the Weibull distribution function (WDF), has been improved by using the moving least squares approximation (MLSA) replace least squares method (LSM). The accuracy of the results obtained by the moving least squares method is shown by two different error analysis tests. In order to implement this method, Osmaniye region, which is rich in wind potential maintenance, has been selected. The root mean square error (RMSE) and mean percentage error (MPE) are used to compare the efficiency of proposed method. In this study, the results of the graphical method developed by the MLSA were compared monthly and yearly with the results obtained according to the least squares method. It was observed that the results of the proposed method in the two error analysis tests were much better. Also, the mean wind speed and average wind power values of the selected region were calculated with the coefficients found by MLSA. These calculated values were compared with actual values. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
43. Application of innovative trend analysis on rainfall time series over Rajsamand district of Rajasthan state.
- Author
-
Pastagia, Jinal and Mehta, Darshan
- Subjects
TIME series analysis ,TREND analysis ,HYDROLOGIC cycle ,CLIMATE change ,WEATHER ,RAINFALL ,WINTER - Abstract
Rainfall is an important part of the hydrological cycle, as well as its variability, and is relevant to drought and floods. Long-term changes in hydrological processes are referred to as climate change for an area. Urbanization, population growth, and economic growth are all having negative effects on the environment. The study of trends in the long term is essential from climatic change and socioeconomic perspectives. Examining the temporal variations in rainfall is crucial because changes in rainfall patterns and distribution can have a significant impact on the amount of water available in a watershed. The objective of the study is to assess the long-term (1902–2021) temporal trends in seasonal (winter, pre-monsoon, monsoon, and post-monsoon) and annual rainfall for the Rajsamand district of Rajasthan state using the innovative trend analysis (ITA) technique. Due to its ability to provide results in graphical form, the ITA approach is a very useful tool for detecting patterns in rainfall time series data. This technique is also used to detect trends as ‘low,’ ‘medium,’ and ‘high,’ which should be considered in future studies on floods ‘high’ and drought ‘low’, respectively. Based on the above study, it is observed that no trend is detected for the annual season, a positive trend is detected in the winter season and a negative trend is detected for pre-monsoon and post-monsoon seasons in some regimes respectively. The ITA of the S-W monsoon also specifies that in the low regime the nature of the trend is increasing and in the high regime nature of the trend is decreasing. This research will serve as a scientific foundation for assessing and mitigating the effect of climate change on the environment to reduce the risk of weather patterns. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
44. A Graphical Approach to Euler’s Method
- Author
-
Tournès, Dominique, Ellerton, Nerida F., Series editor, Clements, M.A. (Ken), Series editor, Barbin, Évelyne, Guichard, Jean-Paul, Moyon, Marc, Guyot, Patrick, Morice-Singh, Catherine, Métin, Frédéric, Bühler, Martine, Tournès, Dominique, Chorlay, Renaud, and Hamon, Gérard
- Published
- 2018
- Full Text
- View/download PDF
45. Graphical Method for Evaluating and Predicting the Human Performance in Real Time
- Author
-
Milici, Mariana-Rodica, Geman, Oana, Chiuchisan, Iuliana, Milici, Laurentiu-Dan, Kacprzyk, Janusz, Series editor, Pal, Nikhil R., Advisory editor, Bello Perez, Rafael, Advisory editor, Corchado, Emilio S., Advisory editor, Hagras, Hani, Advisory editor, Kóczy, László T., Advisory editor, Kreinovich, Vladik, Advisory editor, Lin, Chin-Teng, Advisory editor, Lu, Jie, Advisory editor, Melin, Patricia, Advisory editor, Nedjah, Nadia, Advisory editor, Nguyen, Ngoc Thanh, Advisory editor, Wang, Jun, Advisory editor, Balas, Valentina Emilia, editor, Jain, Lakhmi C., editor, and Balas, Marius Mircea, editor
- Published
- 2018
- Full Text
- View/download PDF
46. A simulation and experimental study on the deep drawing process of SPCC sheet using the graphical method.
- Author
-
Luyen, The-Thanh, Tong, Van-Canh, and Nguyen, Duc-Toan
- Subjects
CARBON steel ,FINITE element method - Abstract
This study presents a method for finite element (FE) simulation of a deep drawing process of a cold-rolled carbon steel (SPCC) sheet material based on the graphical method. First, uniaxial tensile specimens were prepared and experimental tests were conducted to determine the flow stress curves. The calculation of the fracture points at special strain modes (plane strain, uniaxial tensile strain, and biaxial tensile strain) was presented using the modified maximum force criterion (MMFC). After that, the graphical method was adopted for the estimation of the forming limit curve (FLC) based on several hardening laws. FE models for a deep drawing process of the SPCC sheet were then built using the calculated FLCs. Using FE simulations, the fracture heights of cylinder cups formed by the deep drawing process were finally determined and compared with those from experiments. The results showed a good agreement between simulated and measured fracture height with a maximum of 3.6 % deviation. Additionally, simulations and corresponding experiments were performed to investigate the effects of the blank holder force, punch corner radius, and drawing ratio on the fracture height of cylinder cups. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
47. Liquefaction Analysis of Soils according to the New Turkish Building Earthquake Code and Improvement against Liquefaction
- Author
-
Uğur Dağdeviren
- Subjects
liquefaction analysis ,standard penetration test ,ground improvement ,jet grouting ,graphical method ,Disasters and engineering ,TA495 ,Environmental sciences ,GE1-350 - Abstract
One of the damages caused by earthquakes in engineering structures is soil liquefaction-induced damages. Because of the many factors that affect the liquefaction mechanism of soils, the assessment of liquefaction potential is a rather complex problem. In the earthquake, it is the necessary to determine the liquefaction sensitivity of soils and take precautions by estimating possible effects. The stress-based liquefaction analysis, which is the commonly used to determine the liquefaction susceptibility of the soils, has been included in the new Turkish Building Earthquake Code (TBEC). In the usage of this method, the numerous parameters such as the earthquake characteristics, the soil properties, the in-situ and underground water conditions, the properties of equipment used during field studies are needed. Due to the excessive number of parameters and empirical expressions used in the analysis, significant errors can sometimes cause in the soil investigation reports in practice. In this study, in order to make practical use of liquefaction analysis based on standard penetration test defined in TBEC, and to control quickly the performed analyses, the graphics that give the factor of safety against liquefaction of sandy soils were prepared for different depths, groundwater levels, fine contents, and SPT-N values. In addition, cards were developed to determine design parameters such as the stiffness of the columns to be used in the column formation method and the column spacing to be used for the improvement of the liquefiable soils.
- Published
- 2019
- Full Text
- View/download PDF
48. Construction of phase diagrams to estimate phase transitions at high pressures: A critical point at the solid liquid transition for benzene.
- Author
-
Ibrahimoglu, Beycan, Uner, Deniz, Veziroglu, Ayfer, and Karakaya, Fuat
- Subjects
- *
PHASE diagrams , *CRITICAL point (Thermodynamics) , *PHASE transitions , *BENZENE , *SOLID-liquid equilibrium , *BENZENE derivatives - Abstract
Phase diagrams are an integral part of the estimation of material properties in the case of high temperature and pressure. The pressure-temperature (P-T) phase diagram is used to determine the state of aggregation (solid, liquid, gaseous) of a substance under given conditions. This article presents a method to reveal new states in the phase diagram, including the possibility of the plasma state. Using the empirical data of benzene, a critical pressure beyond solid-liquid equilibrium was estimated. It is highly probable that beyond these pressures, benzene may ionize and exhibit plasma behavior. The method proposed in this work for benzene could also be applied to create a comprehensive phase diagram of Hydrogen at certain pressure and temperature. Because the complex behavior of hydrogen, as well as the constant discovery of new varieties and the creation of many different phases of hydrogen makes it very difficult to construct a realistic phase diagram. [Display omitted] • The critical pressure is the highest pressure that a solid-liquid coexists. • Beyond critical pressure, matters may ionize and exhibit plasma behavior. • The plasma state of the matter should be included in the phase diagram. • Graphic method can be used to find critical points of a matter. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
49. Analysis of Solution Pattern of Natural Frequencies by a Graphical Method.
- Author
-
Hasar, Ugur C., Ozturk, Gokhan, Bute, Musa, Ertugrul, Mehmet, and Barroso, Joaquim J.
- Subjects
- *
MEASUREMENT errors , *NOISE measurement , *FOURIER transforms , *SEPARATION of variables , *TIME-frequency analysis - Abstract
We propose a powerful graphical method for evaluating the natural complex frequencies and amplitudes of the layered structures for their electromagnetic characterization. Its advantage is to show a pattern of the location of the natural complex frequencies so that it would be possible to examine how they can move for a possible error in the measurement system. The method is validated by a two-layered structure by comparing the natural complex frequencies and amplitudes computed by the proposed method and the inverse Fourier transform. It has been applied to monitor the effect of noise in a measurement system. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
50. Graphical method for the construction of pairs of 3D skew funiculars in equilibrium with coplanar loads and controlled supports' positions.
- Author
-
Boulic, Léa
- Subjects
- *
EQUILIBRIUM , *BRIDGE design & construction , *ROOF design & construction , *STATICS , *CONSTRUCTION , *RECIPROCALS (Mathematics) - Abstract
Two‐dimensional (2D) funicular structures can be easily generated and controlled by means of simple geometric constructions. These geometric constructions derive from reciprocal relationships between the form and force diagrams of a structure, which form the basis of graphic statics. Unlike in 2D space, in 3D space, similar geometric constructions cannot always be established for the design of three‐dimensional (3D) funicular structures. In some specific cases though, purely geometric procedures requiring no numerical approximations can be defined. In particular, this contribution explores the geometric transformation of 2D funicular structures as a means to graphically generate 3D funicular structures in equilibrium with coplanar loads. A fully graphical method for the construction of such pairs of 3D skew funiculars in equilibrium with coplanar loads and with control over the position of the supports is presented. It is based on geometrical linear relationships between the original and the transformed structures. Ultimately, it is shown how such pairs of 3D skew funiculars can be applied to the design of bridge and roof structures for instance. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
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