584 results on '"performance function"'
Search Results
102. Probabilistic Robustness Analysis and Design of Uncertain Systems
- Author
-
Tempo, R., Dabbene, F., Byrnes, Christopher I., editor, Picci, Giorgio, editor, and Gilliam, David S., editor
- Published
- 1999
- Full Text
- View/download PDF
103. Probabilistic and statistical modeling of loads and forces
- Author
-
Konstantin V. Kurguzov, Igor Fomenko, and Daria Shubina
- Subjects
probabilistic and statistical modeling ,business.industry ,Computer science ,distribution functions ,Probabilistic logic ,lcsh:HD9715-9717.5 ,020101 civil engineering ,Statistical model ,02 engineering and technology ,Structural engineering ,01 natural sciences ,0201 civil engineering ,010101 applied mathematics ,the monte carlo method ,lcsh:Construction industry ,lcsh:Architecture ,loads and forces ,0101 mathematics ,performance function ,business ,reliability assessment ,lcsh:NA1-9428 - Abstract
Introduction. At present, numerical methods enjoy widespread use in construction practice. They enable performing and analyzing complex non-linear, multi-factor models without excessive analytical procedures. However, as a rule, the most complex tasks, performed in a three-dimensional setting with account taken of physical, geometric and other nonlinearities, are performed in deterministic formulations without the analysis of the stochastic nature of physical processes. This seems particularly strange, given that numerical methods are well-suited for modeling stochastic processes. Numerical probabilistic and statistical approaches (PSA) can be applied to simulate and take into consideration various spatiotemporal aspects of the probabilistic nature of loads and forces, structural system resistances, materials and geological terrains. Even the most advanced numerical models of deterministic physical systems are merely a specific case of probabilistic and statistical modeling: they enable obtaining only one value (point) on the whole field of possible implementations, being unable to demonstrate an objective and exhaustive variety of probable outcomes. This article presents a case study of numerical probabilistic and statistical analyses of loads and forces. Methods of research. Materials from different sources, such as reference books, regulatory documents, laboratory test results, as well as available experimental data, were used as input parameters. The principal calculation and analysis of the integral function of loads was performed using the Monte Carlo numerical method of probabilistic and statistical modeling and various theoretical (statistical) and empirical distributions, followed by the quantitative assessment of design loads at various confidence probability values. Results. This study provides an example of the probabilistic and statistical calculation (determination) of the integral function of loads and forces with account taken of different origins of loads and varied input parameter distribution patterns, including empirical distributions. It has proven great importance of accurate description of initial distributions of a random value for the determination of reliable design load values. Conclusions. Probabilistic and statistical approaches have the ability to objectively assess the performance of structural systems based on the quantitative assessment of the probabilistic nature of load factors. These approaches have huge potential for increasing the reliability of buildings and structures and the cost effectiveness of construction projects.
- Published
- 2020
- Full Text
- View/download PDF
104. An efficient particle swarm optimization-joint probability distribution optimization method for structural reliability analysis
- Author
-
Kamran Daneshjou and Hossein Mansourinejad
- Subjects
Mathematical optimization ,Engineering structures ,Computer science ,Mechanical Engineering ,Structural reliability ,Particle swarm optimization ,020101 civil engineering ,Probability density function ,02 engineering and technology ,0201 civil engineering ,Nonlinear system ,020303 mechanical engineering & transports ,0203 mechanical engineering ,Joint probability distribution ,Performance function ,Reliability (statistics) - Abstract
The performance function of many engineering structures and mechanisms is usually complex, highly nonlinear, and described in the implicit form. The reliability analysis of these structures using common methods requires high cost and time. In this paper, a new approach for reliability analysis of engineering structures and mechanisms by using the particle swarm optimization algorithm is presented. The advantages of this method in comparison with the conventional methods are its simplicity and accuracy. In addition, the limitations of the common previously presented methods are eliminated by the proposed method. This approach is based on a new redefinition of most probable point in the reliability analysis. To evaluate the performance and validity of the proposed method, some examples in the reliability analysis of various functions are employed. Finally, the superiority of the proposed method in performance and accuracy is demonstrated and compared to the conventional methods and it can be used for reliability analysis of complicated engineering structures.
- Published
- 2020
- Full Text
- View/download PDF
105. Deployment of roadside units to overcome connectivity gap in transportation networks with mixed traffic
- Author
-
Zhibin Chen, Yafeng Yin, Ye Li, and Srinivas Peeta
- Subjects
Strategic planning ,050210 logistics & transportation ,Cost–benefit analysis ,Computer science ,05 social sciences ,Optimal deployment ,Transportation ,Throughput ,Plan (drawing) ,010501 environmental sciences ,01 natural sciences ,Computer Science Applications ,Network equilibrium ,Transport engineering ,Software deployment ,0502 economics and business ,Automotive Engineering ,Performance function ,0105 earth and related environmental sciences ,Civil and Structural Engineering - Abstract
In the foreseeable future, the traffic stream will be likely mixed with connected automated vehicles (CAVs) and regular vehicles (RVs). In the mixed traffic environment, when following a RV, due to the lack of vehicle-to-vehicle communications, it may take longer time for a CAV to sense and react than a human driver, which results in longer time headway and the loss of highway throughput. To address such a connectivity gap, this paper investigates an infrastructure-based solution, i.e., the deployment of roadside units to help CAVs in the heterogeneous traffic stream. Specifically, it is envisioned that these roadside units can sense vehicles in their coverage areas and provide the beyond-line-of-sight motion information to CAVs to empower them to react proactively, as they would do when following other CAVs. This paper is devoted to the analysis of the impacts of this type of roadside units at a strategic planning stage. In doing so, we first derive an analytical link performance function to capture their impact on the link capacity and travel time, and then develop a network equilibrium model to gauge their effect on travelers’ route choices and thus the flow distribution of both RVs and CAVs across the whole network. This modeling development will allow us to conduct a cost-benefit analysis for a given deployment plan of roadside units. For fair analyses, we further develop an optimization model to determine the optimal deployment plan for a given budget, while focusing on the worst case of its impact, because the flow distribution resulting from our network equilibrium model is not unique. Such a model provides a conservative estimate of the benefit brought by roadside units. Lastly, we offer case studies to demonstrate the models and unveil the potential of such an infrastructure-based solution.
- Published
- 2020
- Full Text
- View/download PDF
106. Effects of Iterative Reconstruction on Image Quality of Pediatric Body Computed Tomography Images
- Author
-
Noriko Kotoura, Rina Muraoka, Yoko Ikeuchi, Shinya Nakano, Masato Kiriki, Katsuhiko Maeda, and Shuhei Aoyama
- Subjects
Materials science ,Noise power spectrum ,medicine.diagnostic_test ,Phantoms, Imaging ,Image quality ,Data Collection ,Hybrid iterative reconstruction ,Computed tomography ,General Medicine ,Iterative reconstruction ,Radiation Dosage ,Optical transfer function ,medicine ,Humans ,Performance function ,Spatial frequency ,Child ,Tomography, X-Ray Computed ,Algorithms ,Biomedical engineering - Abstract
This study evaluated the effects of three types of hybrid iterative reconstruction (IR) on image quality of pediatric body computed tomography images. The image quality components evaluated were noise power spectrum (NPS), task-based modulation transfer function (TTF), and system performance function (SPF). As the IR strength was increased while reducing the radiation dose, the NPS increased in a low-frequency range and the TTF decreased in low-contrast regions. In the low-contrast regions, the calculated SPF decreased over the entire frequency range. Alternatively, in the high-contrast regions, the SPF decreased in the low-frequency regions and increased in the high-frequency regions. The radiation dose reduction using the hybrid IR resulted in the deterioration of the image quality in the low-contrast regions and changes in the spatial frequency characteristics in the high-contrast regions.
- Published
- 2020
- Full Text
- View/download PDF
107. MJERENJE OTPORNOSTI STROJEVA ZA ŠIROKOČELNO ISKAPANJE
- Author
-
Seyed Hadi Hoseini, Behzad Ghodrati, Uday Kumar, and Sasan Heydari
- Subjects
lcsh:TN1-997 ,Computer science ,Process (engineering) ,Maintainability ,drum shearer ,Production (economics) ,time to repair ,ugljen ,sjekačica ,vrijeme popravka ,funkcija uspješnosti ,Resilience (network) ,lcsh:Mining engineering. Metallurgy ,Reliability (statistics) ,Water Science and Technology ,coal ,Measure (data warehouse) ,business.industry ,lcsh:QE1-996.5 ,Coal mining ,Geology ,Geotechnical Engineering and Engineering Geology ,Reliability engineering ,lcsh:Geology ,General Energy ,Quantitative analysis (finance) ,performance function ,General Earth and Planetary Sciences ,business - Abstract
This paper attempts to apply the resilience concept to the mining sector, especially to mining machinery and production systems. The quantitative analysis method using the linear recovery function has been applied. As the core part of the proposed method, it is assumed that in the mining machinery fleet, the performance function falls to a “zero” value immediately after the occurrence of a failure. Therefore, the resilience calculation process runs through the concept of time to repair and machine maintainability. As a case study for the proposed concept, the operation and failure data of the drum shearer machine in Parvadeh longwall mine in Iran is applied. The data pertains to a coal cutting operation in a whole longwall panel over the period of two years. In total, the calculations encompass over 2600 hours of actual operation and 171.8 hours of repair time, which reveals that the studied shearer has a resilience of 96.7 percent. Along with the case study results, it is confirmed by this paper that resilience as a developing concept could be adequately applied to coal mining systems as a support measure for production assurance and reliability., U radu je opisana primjena koncepta otpornosti u rudarstvu, tj. u radu strojeva koji se rabe kod iskapanja i proizvodnje. Uporabljena je linearna funkcija kao kvantitativna analitička metoda. Pretpostavljeno je kako performanse rudarske opreme padaju na nulu odmah nakon događaja koji označava kvar. Slijedom toga izračun otpornosti postupak je koji u obzir uzima vrijeme potrebno za popravak strojeva u prvobitno radno stanje. Studija slučaja načinjena je s podatcima o kvarovima utvrđenim na sjekačima korištenim u iranskome rudniku (s uzdužnim iskapanjem) Parvadeh i obuhvaćaju dvogodišnje razdoblje vađenja ugljena. Kroz to vrijeme obrađeni su podatci za više od 2600 radnih sati te 171,8 sati utrošenih na popravke. Obradom je izračunano kako otpornost promatranih sjekača iznosi 96,7 %. Potvrđeno je kako takva otpornost može biti primijenjena kod rudarenja ugljena kao dodatna varijabla kojom se opisuje stabilnost i pouzdanost vađenja rude.
- Published
- 2020
- Full Text
- View/download PDF
108. New Derivative Formulas for Integral and Probability Functions: Parallel Computations
- Author
-
Uryasev, Stanislav, Pardalos, Panos M., editor, Hearn, Donald, editor, De Leone, Renato, editor, Murli, Almerico, editor, and Toraldo, Gerardo, editor
- Published
- 1998
- Full Text
- View/download PDF
109. PREDICTIVE ASSESSMENT OF TECHNICAL MEANS OF FEED GRAIN PROCESSING FOR LIVESTOCK
- Author
-
Dmitry I. Chistyakov
- Subjects
fodder production ,process model ,performance function ,computational experiment ,scenario. ,Materials of engineering and construction. Mechanics of materials ,TA401-492 - Abstract
A process model for forming technical-and-economic indices in estimating mechanical equipment for feed grain processing for livestock is offered. Predictive estimate of the perspectiveness of the operating devices representation and development is obtained.
- Published
- 2011
110. Constraint-Driven Layout Synthesis
- Author
-
Chang, Henry, Charbon, Edoardo, Choudhury, Umakanta, Demir, Alper, Felt, Eric, Liu, Edward, Malavasi, Enrico, Sangiovanni-Vincentelli, Alberto, Vassiliou, Iasson, Chang, Henry, Charbon, Edoardo, Choudhury, Umakanta, Demir, Alper, Felt, Eric, Liu, Edward, Malavasi, Enrico, Sangiovanni-Vincentelli, Alberto, and Vassiliou, Iasson
- Published
- 1997
- Full Text
- View/download PDF
111. Two gradient descent algorithms for blind signal separation
- Author
-
Yang, H. H., Amari, S., Goos, Gerhard, editor, Hartmanis, Juris, editor, van Leeuwen, Jan, editor, von der Malsburg, Christoph, editor, von Seelen, Werner, editor, Vorbrüggen, Jan C., editor, and Sendhoff, Bernhard, editor
- Published
- 1996
- Full Text
- View/download PDF
112. An Empirical Examination of Financial Performance: Distilling the Essential Causal Factors
- Author
-
Capon, Noel, Farley, John U., Hoenig, Scott, Capon, Noel, Farley, John U., and Hoenig, Scott
- Published
- 1996
- Full Text
- View/download PDF
113. Simulation-Based Reliability Methods
- Author
-
Ayyub, Bilal M., Mccuen, Richard H., and Sundararajan, C., editor
- Published
- 1995
- Full Text
- View/download PDF
114. Explicit formulas, algorithms, and applications to optimization
- Author
-
Thoma, M., editor and Cao, Xi-Ren, editor
- Published
- 1994
- Full Text
- View/download PDF
115. Bentuk dan Fungsi Pertunjukan Ebeg Turangga Edan di Kelurahan Tegalreja Kecamatan Cilacap Selatan Kabupaten Cilacap
- Author
-
Juniati, Nur Endah
- Subjects
Performance Form ,Ebeg ,Performance Function ,Fungsi Pertunjukan ,Bentuk Pertunjukan - Abstract
The Ebeg Turangga Edan performance is one of the traditional folk art groups in Cilacap Regency which uses the Ebeg property which is turned into a horse. The research objective was to describe the form and function of the Turangga Edan Ebeg Performance in Tegalreja Village, Cilacap Selatan District, Cilacap Regency. This research uses qualitative methods, with a structure and function approach. Data collection techniques include observation, interviews, and documentation. The data validity technique used triangulation. Data analysis using data reduction, data presentation, and drawing conclusions. The results of the research reveal that the Ebeg show is patterned into several parts, namely the initial part of performing the rituals carried out by the penimbul (Pawang), the core part of the three-act presentation, the final part marked by a mass mendheman scene and the closing remarks from the pengimbul / elder / chairman of the Turangga Edan association. Ebeg show is formed from the relationship between elements of the show which includes themes, actors / dancers, movement, music, make-up and fashion, property / equipment, stage, lighting / light and sound, appreciators / audience. The function of the Ebeg Turangga Edan performance in the community of Cilacap Regency includes the functions of ceremonial facilities, self-expression, entertainment, shows / performing arts, educational media, therapy / treatment vehicles, and communication media / social interaction tools. The conclusion is that the Ebeg Turangga Edan show is patterned into parts that are united into one show. The Turangga Edan Ebeg show is used by the community as entertainment., Artikel ini bertujuan mendeskripsikan bentuk dan fungsi Pertunjukan EbegTurangga Edan di Kelurahan Tegalreja, Kecamatan Cilacap Selatan, Kabupaten Cilacap. Metode yang digunakan adalahmetode kualitatif, dengan pendekatan struktur dan fungsi. Teknik pengumpulan data meliputi observasi, wawancara, dan dokumentasi. Teknik keabsahan data menggunakan triangulasi. Analisis data dengan menggunakan cara reduksi data, penyajian data, dan menarik kesimpulan. Hasil penelitian mengungkapkan bahwa pertunjukan Ebeg terpola menjadi beberapa bagian yaitu bagian awal melakukan ritual yang dilakukan oleh penimbul(Pawang), bagian inti adanya sajian tiga babak, bagian akhir ditandai dengan adegan mendhemanmassal dan sambutan penutup dari penimbul/sesepuh/ketua paguyuban Turangga Edan. Pertunjukan Ebeg terbentuk dari tata hubungan antar elemen pertunjukan yang meliputi tema, pelaku/penari, gerak, musik, tata rias dan tata busana, property/perlengkapan, tempat pentas, tata lampu/cahaya dan suara, apresiator/penonton. Fungsi pertunjukan EbegTurangga Edan di masyarakat Kabupaten Cilacap meliputi fungsi sarana upacara, ekspresi diri, hiburan, tontonan/seni pertunjukan, media pendidikan, wahana terapi/pengobatan, dan media komunikasi/alat interaksi sosial. Kesimpulannya adalah bentuk pertunjukan Ebeg Turangga Edan terpola menjadi bagian-bagian yang menyatu menjadi satu pertunjukan. Pertunjukan Ebeg Turangga Edan digunakan masyarakat yang berfungsi sebagai hiburan.
- Published
- 2021
116. ASS-GPR: Adaptive Sequential Sampling Method Based on Gaussian Process Regression for Reliability Analysis of Complex Geotechnical Engineering
- Author
-
Xiangpeng Li, Mengyao Li, Long Qian, Zhenyue Ma, and Gang Wang
- Subjects
Nonlinear system ,Kriging ,Computer science ,Ground-penetrating radar ,Soil Science ,Performance function ,Geotechnical engineering ,Sequential sampling ,Reliability (statistics) - Abstract
Reliability analysis of complex geotechnical engineering is time-consuming since its performance function is highly nonlinear and implicit. In this paper, an adaptive sequential sampling m...
- Published
- 2021
- Full Text
- View/download PDF
117. Design and implementation of a DBMS performance assessment tool
- Author
-
Kersten, M. L., Kwakkel, F., Goos, G., editor, Hartmanis, J., editor, Mařík, Vladimír, editor, Lažanský, Jiří, editor, and Wagner, Roland R., editor
- Published
- 1993
- Full Text
- View/download PDF
118. Adaptive output feedback control of nonlinear systems with prescribed performance and MT-filters.
- Author
-
Zhang, Tianping, Li, Shi, Xia, Meizhen, Yi, Yang, and Shen, Qikun
- Subjects
- *
FEEDBACK control systems , *NONLINEAR systems , *ARTIFICIAL neural networks , *CLOSED loop systems , *COMPUTER simulation - Abstract
In this paper, adaptive prescribed performance output feedback control is investigated for a class of nonlinear systems with unmodeled dynamics. Neural networks are used to approximate the unknown nonlinear functions. MT-filters are employed to estimate the unmeasured states. The unmodeled dynamics is dealt with by introducing an available dynamic signal. Adaptive output feedback dynamic surface control and parameter adaptive laws are proposed based on introducing the prescribed performance function and output error transformation. It is proved that all the signals in the closed-loop system are semi-globally uniformly ultimately bounded. Simulation results are provided to demonstrate the effectiveness of the proposed approach. [ABSTRACT FROM AUTHOR]
- Published
- 2016
- Full Text
- View/download PDF
119. Adaptive neural network cascade control system with entropy‐based design.
- Author
-
Zhang, Jianhua, Zhou, Shuqing, Ren, Mifeng, and Yue, Hong
- Abstract
A neural network (NN)‐based cascade control system is developed, in which the primary proportional–integral–derivative (PID) controller is constructed by NN. A new entropy‐based measure, named the centred error entropy (CEE) index, which is a weighted combination of the error cross‐correntropy (ECC) criterion and the error entropy criterion (EEC), is proposed to tune the NN‐PID controller. The purpose of introducing CEE in controller design is to ensure that the uncertainty in the tracking error is minimised and also the peak value of the error probability density function being controlled toward zero. The NN‐controller design based on this new performance function is developed and the convergent conditions are investigated using a linearisation technique. During the control process, the CEE index is estimated by a Gaussian kernel function. Adaptive rules are developed to update the kernel size in order to achieve more accurate estimation of the CEE index. This NN cascade control approach is applied to superheated steam temperature control of a simulated power plant system, from which the effectiveness and strength of the proposed strategy are discussed by comparison with NN‐PID controllers tuned with EEC and ECC criterions. [ABSTRACT FROM AUTHOR]
- Published
- 2016
- Full Text
- View/download PDF
120. A DECISIONAL MODEL FOR TIMEWORN TECHNICAL EQUIPMENTS.
- Author
-
MILTIADE, CÂRLAN, AUREL, COSTEA MARIUS, ISTVAN, CSUZI, and ADRIAN, BETERINGHE
- Subjects
- *
MECHANICAL wear , *ENTROPY , *FUZZY systems , *LINEAR systems , *PERFORMANCE evaluation - Abstract
The paper presents some models designed for managing those technical pieces of equipment that present a certain level of wear and tear accumulated during a long period of time. The precarious operational state of these pieces of equipment can be fixed either through performing maintenance works, or even by disposing the timeworn equipment and replacing it with a more effective and modern equipment. But before its disposal, this equipment can still be used for a certain period of time. The criteria considered in such situations are the effects of the unavailable status of the equipment, plus the associated costs caused by the unavailable status of these pieces of equipment and the discomfort caused by this status. The aim of this study is to highlight the operational degradation - expressed by the alarming entropic level, this fact being as well confirmed by the economic effects of the exploitation of this sort of equipments. [ABSTRACT FROM AUTHOR]
- Published
- 2016
121. AN APPROACH TO ASSESS THE OPERATIONAL POTENTIAL OF TECHNICAL EQUIPMENTS. EXPERTONS AND ENTROPY.
- Author
-
MILTIADE, CÂRLAN, MARIUS - AUREL, COSTEA, and ADRIAN, BETERINGHE
- Subjects
- *
ENTROPY , *INFORMATION theory , *LINEAR systems , *FUZZY systems , *NUMBER theory - Abstract
The aim of this paper is to fundament methods to evaluate, from a time and functional point of view, technical equipments that are described by exploitation conditions like majority redundant k out of k+1". [1],[2]. The purpose is that to identify a certain equipment towards which the management could order preventive maintenance operations. Obviously, finding the optimal decisional solution involves having conclusive information obtained from the exploitation documents (statistical data, technical exploitation instructions, security rules, etc). This type of informations, related to operative behaviour on a certain, pre-established, time interval will be subject to an analysis performed by a group of experts. Their points of view - the assessments of the experts - are to be sequenced on a scale, having a certain number of levels, linear or non-linear (non-linear is preferable)for a greater accuracy of the conclusions of this type of analysis. It is conspicuos that non-objective assessements, generated mainly by the behaviour of the group of experts, will be removed when the findings will be revised using statistical and mathematical tools, suitable for this type of analysis. [ABSTRACT FROM AUTHOR]
- Published
- 2016
122. Goal-Oriented Systems
- Author
-
Klir, George J. and Klir, George J., editor
- Published
- 1991
- Full Text
- View/download PDF
123. Cobwebs and something else
- Author
-
Cavazzuti, Ennio, Beckmann, M., editor, Krelle, W., editor, and Ricci, Gianni, editor
- Published
- 1991
- Full Text
- View/download PDF
124. Enhanced Safety Performance Function for Highway Segments in Oklahoma
- Author
-
Wenying Yu and Joshua Qiang Li
- Subjects
Crash frequency ,Computer science ,021105 building & construction ,0211 other engineering and technologies ,020101 civil engineering ,Performance function ,02 engineering and technology ,Function (mathematics) ,0201 civil engineering ,Civil and Structural Engineering ,Reliability engineering - Abstract
A safety performance function (SPF) is a statistical equation to predict the expected crash frequency for a certain roadway facility, mainly as a function of traffic exposure indicators. Ro...
- Published
- 2021
- Full Text
- View/download PDF
125. AK-PDF: An active learning method combining kriging and probability density function for efficient reliability analysis
- Author
-
Chengning Zhou, Ning-Cong Xiao, Xiaoxu Huang, and Ming J. Zuo
- Subjects
021110 strategic, defence & security studies ,Computer science ,Active learning (machine learning) ,Failure probability ,0211 other engineering and technologies ,Structural reliability ,020101 civil engineering ,Probability density function ,02 engineering and technology ,0201 civil engineering ,Reliability engineering ,Kriging ,Performance function ,Safety, Risk, Reliability and Quality ,Reliability (statistics) - Abstract
An important challenge in structural reliability is to reduce the number of calls to evaluate the performance function, especially the complex implicit performance functions. To reduce the computational burden and improve the reliability analysis efficiency, a new active learning method is developed to consider the probability density function of samples based on the learning function U in an active learning reliability method that combines the kriging and Monte Carlo simulation. In the proposed method, the proposed active learning function contains two parts: part A is based on function U, and part B is based on the probability density function and function U. By changing the weights of parts A and B, the sample points close the limit-state function, and those in the region with a higher probability density function have more weight to be selected compared to the others. Subsequently, the kriging model can be constructed more effectively. The proposed method avoids a large number of time-consuming function evaluations, and the recommended weight is also reported. The performance of the proposed method is evaluated through three numerical examples and one engineering example. The results demonstrate the efficiency and accuracy of the proposed method.
- Published
- 2019
- Full Text
- View/download PDF
126. Integrated method for performance analysis of reliability-based topologically optimized components
- Author
-
B. K. Rout, Arshad Javed, and Joshua Amrith Raj
- Subjects
Computer science ,Mechanical Engineering ,Design of experiments ,Topology optimization ,0211 other engineering and technologies ,02 engineering and technology ,01 natural sciences ,Domain (software engineering) ,Reliability engineering ,010101 applied mathematics ,Robust design ,Performance function ,0101 mathematics ,Reliability (statistics) ,021106 design practice & management - Abstract
The available robust and reliable topology optimization methods provide quick and efficient design output in an uncertain environment. However, the whole domain of performance function remains hidden during this design process. In the interest of the designer, it is required to know the overall behavior of performance functions in deterministic as well as uncertain/realistic environment. The current work achieves this by proposing an integrated methodology, which combines the design of experiments approach and reliability-based topology optimization. The proposed method enables the designer to simulate performance functions in a desired design-factors space, including uncertainties, via reliability value. For this analysis, compliance, maximum deflection, mechanical advantage, and von Mises stress values are selected as performance functions. Volume fraction, applied force, and dimensions or aspect ratio are chosen as design/control factors. The uncertainties of these design factors are captured using reliability-based topology optimization. The uncertainties due to noncontrollable factors such as material property, load direction, and magnitude are incorporated using the design of experiments approach. Under these uncertainties, the performance of topologically optimized problem is simulated for different experimental combinations of the design factors. The experimental combinations for uncertainties and design factors are generated using Taguchi's orthogonal array. Simulated results are analyzed using techniques such as analysis of mean and variance, signal-to-noise ratio, and response surface method. These analyses help in identifying statistical significance of factors and uncertainties, performance variations, and equivalence relation of performance vs. factor. The proposed methodology is illustrated by selecting monolithic structures such as, on MBB, cantilever beam, and force inverter mechanism.
- Published
- 2019
- Full Text
- View/download PDF
127. An efficient algorithm for calculating Profust failure probability
- Author
-
Lyu Zhenzhou, Kaixuan Feng, Chunyan Ling, and Xiaobo Zhang
- Subjects
0209 industrial biotechnology ,Computer science ,Efficient algorithm ,Mechanical Engineering ,Failure probability ,Monte Carlo method ,Aerospace Engineering ,TL1-4050 ,02 engineering and technology ,01 natural sciences ,010305 fluids & plasmas ,Universality (dynamical systems) ,020901 industrial engineering & automation ,Kriging ,0103 physical sciences ,Applied mathematics ,Performance function ,Reliability model ,Motor vehicles. Aeronautics. Astronautics - Abstract
For efficiently estimating the Profust failure probability based on probability input variables and fuzzy-state assumption, a General Performance Function (GPF) expression is established under the strict mathematical derivation for the Profust reliability model. By constructing the GPF, the calculation of the Profust failure probability can be transformed into the calculation of the traditional failure probability. Then various existing methods for the traditional failure probability can be used to estimate the Profust failure probability. Due to the high efficiency of the Adaptive Kriging (AK) model and the universality of the Monte Carlo Simulation (MCS), AK inserted MCS (abbreviated as AK-MCS) has been proven to be an efficient method for estimating the failure probability. Therefore, the AK-MCS combined with the GPF (abbreviated as AK-MCS + GPF) is proposed for estimating Profust failure probability. The proposed method greatly reduces the computational cost while ensuring the accuracy. Finally, four examples are given to validate the proposed AK-MCS + GPF. The results of the examples show the rationality and the efficiency of the proposed AK-MCS + GPF. Keywords: Failure probability, Fuzzy-state assumption, General performance function, Kriging model, Profust reliability, Reliability
- Published
- 2019
128. An efficient Kriging-based subset simulation method for hybrid reliability analysis under random and interval variables with small failure probability
- Author
-
Mi Xiao, Soobum Lee, Amin Toghi Eshghi, Liang Gao, and Jinhao Zhang
- Subjects
Control and Optimization ,Computer science ,Failure probability ,0211 other engineering and technologies ,02 engineering and technology ,Interval (mathematics) ,Computer Graphics and Computer-Aided Design ,Upper and lower bounds ,Computer Science Applications ,020303 mechanical engineering & transports ,0203 mechanical engineering ,Control and Systems Engineering ,Kriging ,Performance function ,Subset simulation ,Projection (set theory) ,Algorithm ,Software ,Reliability (statistics) ,021106 design practice & management - Abstract
This paper proposes an efficient Kriging-based subset simulation (KSS) method for hybrid reliability analysis under random and interval variables (HRA-RI) with small failure probability. In this method, Kriging metamodel is employed to replace the true performance function, and it is smartly updated based on the samples in the first and last levels of subset simulation (SS). To achieve the smart update, a new update strategy is developed to search out samples located around the projection outlines on the limit-state surface. Meanwhile, the number of samples in each level of SS is adaptively adjusted according to the coefficients of variation of estimated failure probabilities. Besides, to quantify the Kriging metamodel uncertainty in the estimation of the upper and lower bounds of the small failure probability, two uncertainty functions are defined and the corresponding termination conditions are developed to control Kriging update. The performance of KSS is tested by four examples. Results indicate that KSS is accurate and efficient for HRA-RI with small failure probability.
- Published
- 2019
- Full Text
- View/download PDF
129. A New Sequential Surrogate Method for Reliability Analysis and its Applications in Engineering
- Author
-
Kunling Song, Yugang Zhang, Xinshui Yu, and Bifeng Song
- Subjects
Mathematical optimization ,General Computer Science ,Computer science ,Markov chain ,0211 other engineering and technologies ,Boundary (topology) ,02 engineering and technology ,symbols.namesake ,0203 mechanical engineering ,classification accuracy ,Kriging ,Feature (machine learning) ,General Materials Science ,Reliability (statistics) ,021106 design practice & management ,Iterative and incremental development ,kriging model ,Failure probability ,General Engineering ,learning strategy ,Markov chain Monte Carlo ,020303 mechanical engineering & transports ,symbols ,Performance function ,lcsh:Electrical engineering. Electronics. Nuclear engineering ,Reliability analysis ,lcsh:TK1-9971 - Abstract
In reliability analysis for the practical engineering problems with the time-consuming model, it has become an important challenge that how to obtain accurate reliability assessment with a minimum number of calls. In order to reduce the computational cost, this paper develops a new sequential surrogate method combining adaptive kriging and Markov chain Monte Carlo simulation with a novel learning strategy for reliability analysis. The proposed method is named AK-MCMC, which takes full advantage of the classification feature of reliability analysis based on the surrogate models, and it can efficiently approximate the classification boundary of the performance function. First, the learning strategy is developed to sequentially pick out the informative samples for updating the experimental design samples. Then, a new stopping criterion is adopted to guarantee the classification accuracy of the constructed kriging model. In this way, the proposed method skillfully makes reliability evaluation independent of an adaptive iterative process, which greatly improves the efficiency of model refinement. Finally, the proposed method is applied to several examples, which contain small failure probability problem, non-linearity problem, and engineering problem with an implicit performance function. In particular, the efficiency of the proposed AK-MCMC method is proved for the problems with small failure probability.
- Published
- 2019
- Full Text
- View/download PDF
130. Modeling the Enveloping Macroscopic Fundamental Diagram Based on the Traffic Assignment With Deterministic User Equilibrium
- Author
-
Xu Zhang, Chunfu Shao, Peng Zhang, Pengfei Wang, and Hao Yue
- Subjects
Transportation planning ,General Computer Science ,Computer science ,Diagram ,General Engineering ,route choice ,Boundary (topology) ,Transportation ,Topology ,Network topology ,mobility ,congested traffic assignment ,macroscopic fundamental diagram (MFD) ,Road networks ,General Materials Science ,Performance function ,lcsh:Electrical engineering. Electronics. Nuclear engineering ,Link (knot theory) ,lcsh:TK1-9971 - Abstract
This paper aims to propose a new analytical method of deriving the enveloping macroscopic fundamental diagram (MFD) in the light of the well-defined sufficient condition and the route choice criterion in a general network. The enveloping MFD is defined to describe the boundary of all scatter points relating the flow rate (vehicles per unit time) to the vehicle accumulation (vehicles) in a road network. The theoretical framework consists of two parts. The first part is a static congested traffic assignment model which is based on the congested link performance function and the deterministic user equilibrium principle under the entirely congested condition. The second part is the new analytical method which is proposed based on the static uncongested and congested traffic assignments with the deterministic user equilibrium, in which the well-defined sufficient condition is satisfied by employing the static traffic assignment models, and the route choice criterion is fulfilled by the deterministic user equilibrium condition (Wardrop's principle). The main findings of this paper are summarized as follows: 1) the enveloping MFD delimits a region where all scatter points are located; 2) the existence and reproducibility of the enveloping MFD in a general network are verified through numerical examples; 3) the proposed method is suggested to be applied to transportation planning for describing and evaluating the macro-characteristics and the performance of road networks and evaluating whether the OD pattern is congruous with the network topology.
- Published
- 2019
131. Laser Marking Hatch Contour Generation
- Author
-
Yufan Li, Dalin Huang, and Yiming He
- Subjects
Zigzag ,business.industry ,law ,Computer science ,ComputingMethodologies_IMAGEPROCESSINGANDCOMPUTERVISION ,Performance function ,Computer vision ,Artificial intelligence ,business ,Laser ,ComputingMethodologies_COMPUTERGRAPHICS ,law.invention - Abstract
Laser marking has been widely used in industrial processing. For different hatching methods, the operating efficiency and the clarity of the marking pattern are also different. Herein, we realize the zigzag parallel and contour parallel hatch of the single-layer and multi-layer contour pattern respectively based on different parameters, evaluate the algorithm, and give optimization strategies.
- Published
- 2021
- Full Text
- View/download PDF
132. Prediction of motorcyclist traffic crashes in Cartagena (Colombia): development of a safety performance function
- Author
-
Francisco J. López-Valdés, Holman Ospina-Mateus, Shib Sankar Sana, and Leonardo Augusto Quintana Jiménez
- Subjects
050210 logistics & transportation ,Negative binomial regression ,LEMB ,Crashes ,05 social sciences ,Negative binomial distribution ,Motorcycle, crashes ,Management Science and Operations Research ,Computer Science Applications ,Theoretical Computer Science ,Transport engineering ,Safety performance function ,Empirical Bayesian approach ,Geography ,Traffic volume ,Kilometer ,Motorcycle ,0502 economics and business ,0501 psychology and cognitive sciences ,Performance function ,Prone-section ,Road traffic ,050107 human factors ,Road user - Abstract
Motorcyclists account for more than 380 000 deaths annually worldwide from road traffic accidents. Motorcyclists are the most vulnerable road users worldwide to road safety (28% of global fatalities), together with cyclists and pedestrians. Approximately 80% of deaths are from low- or middle-income countries. Colombia has a rate of 9.7 deaths per 100 000 inhabitants, which places it 10th in the world. Motorcycles in Colombia correspond to 57% of the fleet and generate an average of 51% of fatalities per year. This study aims to identify significant factors of the environment, traffic volume, and infrastructure to predict the number of accidents per year focused only on motorcyclists. The prediction model used a negative binomial regression for the definition of a Safety Performance Function (SPF) for motorcyclists. In the second stage, Bayes’ empirical approach is implemented to identify motorcycle crash-prone road sections. The study is applied in Cartagena, one of the capital cities with more traffic crashes and motorcyclists dedicated to informal transportation (motorcycle taxi riders) in Colombia. The data of 2884 motorcycle crashes between 2016 and 2017 are analyzed. The proposed model identifies that crashes of motorcyclists per kilometer have significant factors such as the average volume of daily motorcyclist traffic, the number of accesses (intersections) per kilometer, commercial areas, and the type of road and it identifies 55 critical accident-prone sections. The research evidences coherent and consistent results with previous studies and requires effective countermeasures for the benefit of road safety for motorcyclists.
- Published
- 2021
133. Crash- and Simulation-Based Safety Performance Evaluation of Freeway Rest Area
- Author
-
Hyeonseo Kim, Mohamed Abdel-Aty, Nuri Park, Kyeongjoo Kwon, and Juneyoung Park
- Subjects
traffic simulation ,Computer science ,Geography, Planning and Development ,TJ807-830 ,Crash ,Management, Monitoring, Policy and Law ,TD194-195 ,Renewable energy sources ,Acceleration ,0502 economics and business ,0501 psychology and cognitive sciences ,GE1-350 ,Simulation based ,050107 human factors ,Simulation ,safety performance ,Rest (physics) ,050210 logistics & transportation ,rest area ,Environmental effects of industries and plants ,Renewable Energy, Sustainability and the Environment ,05 social sciences ,surrogate safety ,Traffic simulation ,Modification factor ,Performance results ,crash modification factor ,Environmental sciences ,Performance function - Abstract
The main objective of this study was to evaluate the safety effects caused by altering the lengths of deceleration and acceleration lanes at rest areas on expressways in Korea. Although general conclusions can be found through crash-based safety analysis, to examine more specific optimal conditions considering various traffic conditions, this study proposes a novel framework to explore and evaluate crash-based and simulation-based safety performances. For this purpose, the safety performance function (SPF) and crash modification factor (CMF) were developed to reflect real-world safety impacts. To consider nonlinear trends of the parameters, nonlinearizing link functions were introduced into the analysis. Two types of simulation analyses were conducted to (1) find the combination of surrogate safety measures (SSMs) that best fit with the crash-based safety performance results and (2) determine the optimal lengths of deceleration lane and acceleration lanes for different traffic conditions. The results showed that the best length of deceleration lane of a rest area is between 240 and 260 m, depending on the traffic conditions. The results also indicated that the optimal length of acceleration lane of a rest area is between 385 and 400 m, depending on the traffic parameters. The findings of this study could be used to determine the safety solutions with a micro-traffic simulator.
- Published
- 2021
134. Sensitivity and Correlation Analysis of Double-Layer Cylindrical Reticulated Shell Considering Several Performance Functions.
- Author
-
LI Hui-Jun, FENG Xue, CHENG Zhen-Xing, LI Ming-Fu, and LI Guang-De
- Subjects
- *
CYLINDRICAL shells , *SENSITIVITY analysis , *STATISTICAL correlation , *PERFORMANCE evaluation , *RANDOM variables , *MECHANICAL behavior of materials - Abstract
Reliability, sensitivity between random variables and response, and correlation between responses of double-layer cylindrical reticulated shells with three different span-to-rise ratios are deeply investigated, furthermore the effects of different kinds of random variables and different positions of random variables on reliability and sensitivity between random variable and response are also investigated in details. Cross-sectional area, yielding strength and modulus of elasticity of members and external vertical load are defined as one or more random variables respectively according to their layouts in the reticulated shells, and their effects on sensitivity are substantially carried out. Subsequently, two cases in all are taken into account based on the different classification of random variables. Three performance functions, e.g., the maximal deflection, the total plastic strain energy, the number of yielding members, are taken into consideration for two cases, and correlations among the above performance functions are investigated. [ABSTRACT FROM AUTHOR]
- Published
- 2015
- Full Text
- View/download PDF
135. Efficient Robust Geotechnical Design of Drilled Shafts in Clay Using a Spreadsheet.
- Author
-
Khoshnevisan, Sara, Gong, Wenping, Juang, C. Hsein, and Atamturktur, Sez
- Subjects
- *
GEOTECHNICAL engineering , *CLAY , *COST control , *SOIL mechanics , *SEDIMENTS - Abstract
This paper presents an efficient robust geotechnical design (RGD) approach that considers performance requirements, design robustness, and cost efficiency simultaneously. In this paper, design robustness is measured via the variation in the performance function of concern that can be evaluated using reliability analysis. Furthermore, the performance requirements of the system are also evaluated using reliability analysis. Thus, the evaluation of design robustness and the evaluation of performance requirements share common computational steps, referred to herein as computational coupling. This coupling for computational efficiency is a significant feature of the proposed RGD approach. Within the framework of the proposed RGD approach, design robustness, cost efficiency, and performance requirements can be considered simultaneously by means of multiobjective optimization. Furthermore, a practical and efficient procedure is developed for such optimization using a feature resident in a popular spreadsheet program. Through an example of the design of a drilled shaft in clay, the effectiveness of this new RGD approach is demonstrated. The results show that the hard-to-control variability resulting from construction variation, variable loading conditions, model errors, and uncertain geotechnical parameters in the design of drilled shafts in clay can be effectively considered with the proposed RGD approach. [ABSTRACT FROM AUTHOR]
- Published
- 2015
- Full Text
- View/download PDF
136. Fixed-Time Fuzzy Adaptive Fault-Tolerant Control for Hypersonic Flight Vehicles Using a New Prescribed Performance Function
- Author
-
Dingshan Sun, Yinghui Li, Ju Park, Zehong Dong, and Maolong Lv
- Subjects
Computer science ,Fixed time ,Control theory ,Control (management) ,Hypersonic flight ,Fault tolerance ,Performance function ,Fuzzy adaptive - Abstract
This article proposes a new fixed-time fuzzy adaptive fault-tolerant control methodology for the longitudinal dynamics of hypersonic flight vehicles (HFVs) in the presence of actuator faults, uncertain dynamics and external disturbances. In contrast with the conventional fixed-time control schemes that typically contain the fractional powers of errors in their designs, this work develops a low-complexity control structure in the sense of removing the dependence on the need of above-mentioned fractional power terms by means of prescribed performance control (PPC) method. Different from the most existing PPC approaches where the initial conditions of tracking errors are required to be known, the newly proposed prescribed performance function (PPF) can relax such restrictions through choosing properly small initial values of PPF. Fuzzy logic systems (FLSs) are employed to handle unknown dynamics and minimal learning parameter (MLP) technique is incorporated into the design for the purpose of alleviating computation burden. Closed-loop stability is rigorously proved via Lyapunov stability theory and simulation results are eventually given to validate the effectiveness of the proposed control strategy.
- Published
- 2021
- Full Text
- View/download PDF
137. Time-Dependent Structural Reliability Assessment for Nonstationary Non-Gaussian Performance Functions
- Author
-
Yan-Gang Zhao, Yu Leng, Chun-Qing Li, Chao-Huang Cai, and Zhao-Hui Lu
- Subjects
Mechanical Engineering ,Gaussian ,Structural reliability ,020101 civil engineering ,02 engineering and technology ,0201 civil engineering ,symbols.namesake ,020303 mechanical engineering & transports ,Transformation (function) ,0203 mechanical engineering ,Mechanics of Materials ,symbols ,Quantitative Biology::Populations and Evolution ,Applied mathematics ,Performance function ,Mathematics - Abstract
In this paper, a new analytical formula is proposed to determine the mean outcrossing rate of nonstationary non-Gaussian performance functions. The performance function is firstly transform...
- Published
- 2021
- Full Text
- View/download PDF
138. Local Reliability Based Sensitivity Analysis with the Moving Particles Method
- Author
-
Carsten Proppe
- Subjects
021110 strategic, defence & security studies ,021103 operations research ,Computer science ,Failure probability ,0211 other engineering and technologies ,Estimator ,02 engineering and technology ,Variance (accounting) ,Extension (predicate logic) ,Reliability ,Multilevel Splitting ,Industrial and Manufacturing Engineering ,Partial derivative ,Moving Particles ,Performance function ,Sensitivity (control systems) ,ddc:620 ,Local Sensitivity Analysis ,Safety, Risk, Reliability and Quality ,Algorithm ,Engineering & allied operations ,Reliability (statistics) - Abstract
Local reliability sensitivity methods aim at determining the partial derivatives of the failure probability or the reliability index with respect to model parameters. For efficient local reliability based sensitivity analysis, it is important to avoid repeated evaluations of the performance function. To this end, an extension of the moving particles method to local reliability based sensitivity analysis is presented that is completely based on the already evaluated samples for the reliability estimate and thus avoids repeated evaluations of the performance function. In order to further reduce the variance of the estimator and to increase the efficiency, a multilevel variant of the estimator is proposed. The method is discussed in detail and illustrated by means of examples.
- Published
- 2021
- Full Text
- View/download PDF
139. Reliability analysis using a multi-metamodel complement-basis approach
- Author
-
Rui Teixeira, Beatriz Martinez-Pastor, Alan O'Connor, and Maria Nogal
- Subjects
021110 strategic, defence & security studies ,polynomial chaos expansion ,021103 operations research ,Polynomial chaos ,Computer science ,complement-basis ,0211 other engineering and technologies ,02 engineering and technology ,adaptive metamodeling ,response surface method ,Industrial and Manufacturing Engineering ,Reliability engineering ,Metamodeling ,Kriging ,Compatibility (mechanics) ,A priori and a posteriori ,Performance function ,reliability analysis ,Safety, Risk, Reliability and Quality ,multiple metamodel selection - Abstract
The present work discusses an innovative approach to metamodeling in reliability that uses a field-transversal rationale. Adaptive metamodeling in reliability is characterized by its large spectra of models and techniques with different assumptions. As a result, the reliability engineer is frequently faced with the highly challenging task of selecting an appropriate model or technique with limited a priori knowledge about the performance function that defines the problem of reliability. To tackle this challenge, a complement-basis is proposed for adaptive metamodeling. It consists in using a batch of multiple metamodels or techniques that, accordingly to an activation criterion, are selected to solve the reliability analysis. This activation is set to depend on the model synergy with the problem in-hand. In the present work the leave-one-out loss is applied as evaluator of compatibility, and results show that the absolute loss successfully performs as an activator. A metamodel-independent learning approach and stopping criterion are implemented to study the proposed approach in five representative examples. Results show that the complement-basis allows to increase the efficiency of the reliability analysis through the selection of adequate metamodels, which is indicative of the untapped potential that further transversal research may add to metamodeling in reliability analysis.
- Published
- 2021
140. Cross-coupling control of dexterous hand based on neuron networks.
- Author
-
Gu, Haiwei, Fan, Shaowei, Zhang, Yuanfei, Liu, Yiwei, and Jin, Minghe
- Abstract
In this paper, the author proposes a cross-coupling control approach based on neuron network, of which multiple parameters can be adjusted on line. According to the demand on the convergence of synchronization error in cross-coupling control, synchronization error item is introduced in this method to improve the performance function of BP (back propagation) neuron network, therefore it decreases synchronization error and meanwhile realizes the real-time adjustment of multiple parameters. The results of experiments show that compared with cross-coupling control method of which the parameters are stable, the method proposed in the paper holds the advantage that it can decrease position error and increase the stability of position tracking. [ABSTRACT FROM PUBLISHER]
- Published
- 2012
- Full Text
- View/download PDF
141. A general hierarchical ensemble-learning framework for structural reliability analysis.
- Author
-
Zhou, Changcong, Zhang, Hanlin, Valdebenito, Marcos A., and Zhao, Haodong
- Subjects
- *
STRUCTURAL reliability , *HIERARCHICAL Bayes model , *SURFACE states - Abstract
• Propose a general hierarchical ensemble-learning framework for reliability analysis. • Two-layer models cooperate with each other to fit the limit state function. • The entire training process is divided into three different phases. • A method called CESM-ELF is proposed to check the framework's effectiveness. • The proposed framework can improve the prediction accuracy of ensemble-learning. Existing ensemble-learning methods for reliability analysis are usually developed by combining ensemble-learning with a learning function. A commonly used strategy is to construct the initial training set and the test set in advance. The training set is used to train the initial ensemble model, while the test set is adopted to allocate weight factors and check the convergence criterion. Reliability analysis focuses more on the local prediction accuracy near the limit state surface than the global prediction accuracy in the entire space. However, samples in the initial training set and the test set are generally randomly generated, which will result in the learning function failing to find the real "best" update samples and the allocation of weight factors may be suboptimal or even unreasonable. These two points have a detrimental impact on the overall performance of the ensemble model. Thus, we propose a general hierarchical ensemble-learning framework (ELF) for reliability analysis, which consists of two-layer models and three different phases. A novel method called CESM-ELF is proposed by embedding the classical ensemble of surrogate models (CESM) in the proposed ELF. Four examples are investigated to show that CESM-ELF outperforms CESM in prediction accuracy and is more efficient in some cases. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
142. Probabilistic Seismic Demand Analysis of Structures Using Reliability Approaches
- Author
-
Mahmoud Bayat, Paul Ziehl, Mehdi Kia, and A. Amini
- Subjects
Earthquake engineering ,Geophysics ,Demand analysis ,Computer science ,Probabilistic logic ,Reliability methods ,Performance function ,Geotechnical Engineering and Engineering Geology ,Oceanography ,Reliability (statistics) ,First generation ,Reliability engineering - Abstract
The Probabilistic Seismic Demand Analysis (PSDA) which is frequently implemented in the first generation performance-based earthquake engineering quantifies seismic behavior of a structure by computing mean annual frequency of exceeding a specific value of a desired demand parameter given all anticipated earthquakes. This framework, based on the total probability integration formula, provides a technical basis on which aleatory uncertainties, uncertainties originated due to inherent randomness of the phenomena, are explicitly addressed. However, variability in the mean value of different model parameters, referred to as epistemic uncertainties and mainly due the finite-sample size of observations, is neglected. In this study, as an alternative to total probability integration, a reliability-based formulation tailored to effortlessly reflect both aleatory and epistemic uncertainties is put-forward to perform unified PSDA. Next, as an application of the proposed methodology, a reliability-based seismic demand curve of a 4-story example building is developed. Results demonstrate that the Second-Order Reliability Method (SORM) and important sampling method (ISM) along with multi-step Monte Carlo simulation (MSMCS) methods are appropriate candidates for computing reliability-based PSDA with differentiable and nondifferentiable performance functions, respectively.
- Published
- 2020
- Full Text
- View/download PDF
143. Inversion analysis to determine design parameters for reliability assessment in pavement structures.
- Author
-
Mun, Sungho
- Subjects
- *
PERFORMANCE of pavements , *PARAMETER estimation , *CIVIL engineering , *RELIABILITY in engineering , *SIMPLEX algorithm - Abstract
Reliability assessment has been used to evaluate the performance of pavement structures. However, probabilistic inversion analysis of pavement structure design has not yet been tested to determine the design parameters of the pavement performance function, given a specified reliability index. In this study, a limit state function numerical calculation and the inversion technique of the Nelder-Mead simplex algorithm were used to determine the design parameters for the pavement performance function. The method of moments was used to develop the forward limit state function, which was then compared to Monte Carlo simulations; the comparison indicated good agreement between the two methods. Additionally, several cases were studied to determine the design parameters of the pavement performance function for the reliability index specified in this study. The case studies indicated that the structure number significantly affected the pavement performance function. [ABSTRACT FROM AUTHOR]
- Published
- 2014
- Full Text
- View/download PDF
144. Reliability Assessment of Damaged RC Moment-Resisting Frame against Progressive Collapse under Dynamic Loading Conditions.
- Author
-
Huang, Zhiwei, Li, Bing, and Sengupta, Piyali
- Subjects
- *
REINFORCED concrete , *DYNAMIC testing of materials , *PRESSURE , *MONTE Carlo method , *DEFORMATIONS (Mechanics) - Abstract
Reinforced concrete (RC) structures when subjected to sudden destruction of a column by blast pressure, experience dynamic effects in its response. Hence, reliability assessment of the damaged ductile frame against progressive collapse under dynamic loading conditions is conducted in this research. This paper aims at establishing three performance functions, two of which will consider structural collapse due to lack of strength and deformation capacity respectively while the third will incorporate the shear response of structural components for the weakest collapse mechanism. Since any of the performance functions may lead to structural collapse, a global performance function of the damaged structure is developed by considering the minimum of the functions. The results are then used in conjunction with Monte Carlo Simulation (MCS) to estimate the reliability of the damaged structure. A numerical example of a four storey RC frame is presented to address the applicability of the proposed approach and the effects of different structural parameters on its reliability against progressive collapse after the sudden column loss are investigated thereafter. [ABSTRACT FROM AUTHOR]
- Published
- 2014
- Full Text
- View/download PDF
145. An Effective Kriging-based Approach for System Reliability Analysis with Multiple Failure Modes
- Author
-
Chengning Zhou, Qing Li, Ning-Cong Xiao, Wei Gao, and Ming J. Zuo
- Subjects
Surrogate model ,Computer science ,Kriging ,Component (UML) ,Failure probability ,Performance function ,Multiple failure ,Reliability (statistics) ,Reliability engineering - Abstract
Kriging-based surrogate model is widely adopted in the area of component reliability analysis, thanks to its computational efficiency. However, surrogate models employed in component reliability analysis can not be employed directly in system reliability analysis. In this paper, an effective krigingbased system reliability analysis approach is proposed based on AK-SYS. In the proposed method, the best next samples are selected from the safe region or failure region, and samples in the areas that have little contribution to the composite performance function are avoided. The efficiency and accuracy of the proposed method are illustrated via a numerical example.
- Published
- 2020
- Full Text
- View/download PDF
146. Moment Method with Box–Cox Transformation for Structural Reliability
- Author
-
Chao-Huang Cai, Yan-Gang Zhao, and Zhao-Hui Lu
- Subjects
0209 industrial biotechnology ,Computer science ,Mechanical Engineering ,Structural reliability ,020101 civil engineering ,02 engineering and technology ,Power transform ,0201 civil engineering ,Reliability engineering ,Moment (mathematics) ,020901 industrial engineering & automation ,Mechanics of Materials ,Performance function ,Reliability (statistics) - Abstract
Structural reliability analysis involving highly nonnormally distributed performance functions or relatively small failure probabilities is still a challenging problem in engineering practi...
- Published
- 2020
- Full Text
- View/download PDF
147. Cable Reliability Assessments for Cable-Stayed Bridges using Identified Tension Forces and Monitored Loads
- Author
-
Lin Chen, Limin Sun, and Ning Hou
- Subjects
business.industry ,Computer science ,Tension (physics) ,Performance function ,Building and Construction ,Structural engineering ,Cable stayed ,Structural health monitoring ,business ,Reliability (statistics) ,Civil and Structural Engineering - Abstract
The reliability of stay cables is critical to the safety of cable-stayed bridges. This paper investigates and compares reliability assessments of stay cables by using identified cable tens...
- Published
- 2020
- Full Text
- View/download PDF
148. Easy-to-Use Ideation Technique Based on Five Cross-Industry Analogies Enhances Engineering Creativity of Students and Specialists
- Author
-
Pavel Livotov
- Subjects
Copying ,Management science ,Computer science ,media_common.quotation_subject ,Ideation ,Creativity ,law.invention ,Identification (information) ,law ,TRIZ ,Performance function ,Creative thinking ,Drawback ,media_common - Abstract
Cross-Industry Innovation is commonly understood as identification of analogies and interdisciplinary transfer or copying of technologies, processes, technical solutions, working principles or models between industrial sectors. In general, creative thinking in analogies belongs to the efficient ideation techniques. However, engineering graduates and specialists frequently lack the skills to think across the industry boundaries systematically. To overcome this drawback an easy-to-use method based on five analogies has been evaluated through its applications by students and engineers in numerous experiments and industrial case studies. The proposed analogies help to identify and resolve engineering contradictions and apply approaches of the Theory of Inventive Problem Solving TRIZ and biomimetics. The paper analyses the outcomes of the systematized analogies-based ideation and outlines that its performance continuously grows with the engineering experience. It defines metrics for ideation efficiency and ideation performance function. Finally, a comparison with other TRIZ inventive techniques, such as nine fields of the Substance-Field Analysis and 40 Inventive Principles is presented.
- Published
- 2020
- Full Text
- View/download PDF
149. A hybrid directional step method for minimum performance target point search
- Author
-
Yongqin Wang, Weiqi Du, and Yuanxin Luo
- Subjects
Computer science ,Applied Mathematics ,Computation ,02 engineering and technology ,01 natural sciences ,010101 applied mathematics ,020303 mechanical engineering & transports ,0203 mechanical engineering ,Robustness (computer science) ,Modeling and Simulation ,Performance function ,0101 mathematics ,Algorithm ,Step method - Abstract
The existing step size methods aim to success in the convergence of searching the minimum performance target point in the reliability analysis. However, these methods cannot guarantee that the performance function value is smaller than that of previous point. This results in the redundant computation during the search process. In this paper, a new step method called hybrid directional step method is proposed to improve the efficiency of search process. The proposed method can keep the performance function values of iterations presenting a decreasing sequence and quickly converge to the minimum performance target point. The proposed method is compared with some existing methods through several numerical examples. The results show that the proposed hybrid directional step method presents good robustness and more efficient computation in practical application.
- Published
- 2018
- Full Text
- View/download PDF
150. Pedestrian hybrid beacon signals: Identifying characteristics associated with negative consequences to reduce danger at mid-block locations
- Author
-
Ajinkya S. Mane, Venu Madhav Kukkapalli, and Srinivas S. Pulugurtha
- Subjects
050210 logistics & transportation ,Variables ,Health Policy ,media_common.quotation_subject ,05 social sciences ,Public Health, Environmental and Occupational Health ,Transportation ,Pedestrian ,Predictor variables ,Pollution ,Signal ,Pearson product-moment correlation coefficient ,symbols.namesake ,Bayes' theorem ,0502 economics and business ,Statistics ,symbols ,Environmental science ,0501 psychology and cognitive sciences ,Performance function ,Safety, Risk, Reliability and Quality ,Safety Research ,050107 human factors ,media_common ,Block (data storage) - Abstract
The focus of this paper is on an evaluation of negative consequences due to the installation of pedestrian hybrid beacon (PHB) signals and to identify associated characteristics to proactively plan and reduce danger at mid-block locations. Data for thirteen mid-block locations with a PHB signal in the city of Charlotte, North Carolina was gathered to conduct before-after analysis using Empirical Bayes (EB) method. Data for fifty-nine mid-block locations without a PHB signal or similar treatment was considered as control locations for developing a safety performance function (SPF). The on-network characteristics were considered as the predictor variables, while the number of all crashes from 2011 to 2013 was considered as the dependent variable. The SPF was validated using 2014 data. A calibration factor was applied to estimate the number of all crashes at each PHB location. The results obtained from before-after EB analysis showed that the actual number of all crashes are relatively higher after the installation of PHB signals at five out of the thirteen PHB signal locations when compared with the estimated number of all crashes, had the PHB signal not been installed. Pearson correlation coefficients were estimated and used to examine the relationship between the number of all crashes and predictor variables such as demographic, socio-economic, land use, and on-network characteristics within the vicinity of each PHB signal location. The findings indicate that installing PHB signals at mid-block locations along high traffic volume, high-speed and wide roads, and, near office, multi-family, retail, and vertical mixed land use areas will lead to an increase in the number of all crashes after its installation.
- Published
- 2018
- Full Text
- View/download PDF
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.