Search for: model-based
Total 99 records
Article Frontiers in Artificial Intelligence and Applications ; Volume 246 , 2012 , Pages 57-72 ; 09226389 (ISSN) ; 9781614991243 (ISBN) ; Ramsin, R ; Fujita H ; Revetria R ; Sharif University of Technology
Quality is one of the most important issues in the context of agile and lightweight methodologies. These methodologies recommend automated testing as the main method for quality assurance; however, they are plagued with several deficiencies in this regard, including complex and difficult-to-maintain test case scripts. Model-based testing is an approach for automating the test creation process through replacing individual test-case design with abstract models. In this paper, we explore a set of patterns based on current methods used in model-based testing which can be used to ameliorate the abovementioned deficiencies in agile/lightweight methodologies. We then demonstrate how these patterns...
M.Sc. Thesis Sharif University of Technology ; Heidari, Moghadam
In the present research, model-based reasoning is introduced and explained based on Giere’s explanation of model. In other word, this research could be regarded as a reconstruction of model in Giere’s books and papers due to prpose a clear explanation of model-based reasoning. In the second chapter, after the introduction, the concept of model in Giere’s distinguished book, “Explainnig Science: A Cognitive Approach” (1988) is introduced and analyzed. In the second chapter, however, the concept of model in Giere’s recent works is traced. “An agent-based account of model” and “focusing on functionality rather than ontology” could be explained as the two important differences between his...
Article International Journal of Software Engineering and Knowledge Engineering ; Volume 22, Issue 8 , 2012 , Pages 1085-1102 ; 02181940 (ISSN) ; Mirian Hosseinabadi, S. H ; Sharif University of Technology
Test Driven Development (TDD), as a quality promotion approach, suffers from some shortages that discourage its usage. One of the most challenging shortcomings of TDD is the low level of granularity and abstraction. This may lead to production of software that is not acceptable by the end users. Additionally, exploiting of TDD is not applicable in the enterprise systems development. To overcome this defect, we have merged TDD with Model Based Testing (MBT) and suggested a framework named Model Based Test Driven Development (MBTDD). According to TDD, writing test cases comes before programming, and based on our improved method of TDD, modeling precedes writing test cases. To validate the...
Article 27th Iranian Conference on Electrical Engineering, ICEE 2019, 30 April 2019 through 2 May 2019 ; 2019 , Pages 929-932 ; 9781728115085 (ISBN) ; Haeri, M ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc 2019
A model-based algorithm is proposed and tested using the simulator and operation data of a plastic pipeline prototype to locate multiple non-simultaneous leaks in the pipeline. A combination of an extended Kalman filter and obtained relations from the steady state response is used in order to tackle the problem of multi-leak localization. To achieve the mentioned relations, a real pipe with two leaks is equated to a virtual pipe with a single virtual equivalent leak
Article Mechanics Research Communications ; Vol. 62 , December , 2014 , pp. 83-88 ; ISSN: 00936413 ; Yousefi-Koma, A ; Pishkenari, H. N ; Sharif University of Technology
Conventional continuum theory does not account for contributions from length scale effects. Failure to include size-dependent contributions can lead to underestimates of deflection and stresses of micro and nanobeams. This research aims to use strain gradient elasticity theory to model size-dependent behavior of small beams. In this regard, Young's modulus and length scale parameters of poly silicon are estimated by fitting the predicted static pull-in voltages to the reported experimental results in the literature. The results demonstrate that decreasing the beam thickness results in higher pull-in voltage, lower deflection and lower sensitivity to axial stress and mid-plane stretching in...
Article IEEE International Symposium on Industrial Electronics ; 2012 , Pages 780-785 ; 9781467301589 (ISBN) ; Jahed, M ; Sharif University of Technology
In this paper, a model-based dynamics equation for the needle movement through the soft tissue is developed. A model-based control scheme which uses the force estimation calculated through the simulated tissue deformation data and the dynamic finite element as the tissue model is proposed. To compare the performance of the proposed controller, a PD controller is also used for the proposed needle dynamics equation. It is shown that even with uncertainty in model parameters; the mode-based controller outperforms the PD controller. Furthermore, although increasing the controller gain improves the performance of PD, but the model-based controller's performance is still superior
Model based compressor fault identification using stage stacking technique and nonlinear diagnostic systems, Article Proceedings of the ASME Turbo Expo, 9 June 2008 through 13 June 2008, Berlin ; Volume 2 , 2008 , Pages 213-221 ; 9780791843123 (ISBN) ; Khaledi, H ; Ghofrani, M. B ; International Gas Turbine Institute ; Sharif University of Technology
Compressor fault identification is an important part of gas turbine diagnostic systems. Model based techniques have been used widely in this field. In this paper the performance of two compressors has been simulated using stage stacking method. One of them is the NASA 10 stage constant tip diameter compressor. The other one is the Siemens V94.2 engine's compressor. Then a new and more real compressor fault model is introduced and the effect of different faults on compressor performance has been studied. In this paper an intelligent fault diagnostic system has been developed which is able to detect different faults of the compressor. In all of the cases of faults, degradation in inlet flow...
Modeling in-and-out-of-water impact on all-electric ship power system considering propeller submergence in waves, Article 2021 IEEE Transportation Electrification Conference and Expo, ITEC 2021, 21 June 2021 through 25 June 2021 ; 2021 , Pages 533-538 ; 9781728175836 (ISBN) ; Peyghami, S ; Parniani, M ; Blaabjerg, F ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc 2021
Despite the advantages of employing an electric propulsion system in All-Electric Ships (AES), additional power fluctuation sources have emerged in the ship power system as a result. Since the propellers are the primary power consumers in the AES, these fluctuations may significantly affect its power system power quality. Thus, for optimal performance of the ship power system, these fluctuations need to be rigorously investigated at the design level of vessels. Waves collision is one of the critical conditions where propellers inject power fluctuations into the ship power system. Therefore, a comprehensive model is essential to analyze the propellers in-and-out-of-water effect on the ship...
Article IET Software ; Volume 13, Issue 5 , 2019 , Pages 327-337 ; 17518806 (ISSN) ; Ramsin, R ; Sharif University of Technology
Institution of Engineering and Technology 2019
This study presents a process-driven view on the use of model-based testing (MBT) in agile/lightweight processes. It argues that process-related aspects of MBT and agile processes should be explicitly considered in any practical MBT approach intended for use in agile development (AD). It demonstrates that an effective MBT approach for lightweight processes has to specify how MBT activities are integrated into a development process, how and when MBT artefacts are generated in relation to other development artefacts, and who would carry out MBT activities. Accordingly, a set of integration criteria is introduced for complete incorporation of MBT into agile/lightweight processes. The...
M.Sc. Thesis Sharif University of Technology ; Mirian Hosseinabadi, Hassan
Less than a decade ago, Test Driven Development (TDD) emerged as a quality assurance approach and applied in agile software developments. In this method, test cases act as software development driver and a new piece of code is added just to satisfy the corresponding test case in the test repository. Although the results of applying TDD show its success in software quality promotion, but the method suffers from some limitations and shortcomings that make its usage hard in complicated and enterprise software projects, particularly in the industry. The goal of the following research is to mitigate the drawbacks of TDD and improve the method in order to make it more applicable for complicated...
M.Sc. Thesis Sharif University of Technology ; Ramsin, Raman
In the modern software era, testing plays an invaluable role in software development as a quality assurance measure. Estimates have been made that up to 50% of effort and resources in software projects are allocated to testing. Model based testing (MBT) is one of the important stages of model driven development (MDD), which involves creating test cases from software models. When test cases are created from models, they reside at a higher level of abstraction, therefore creating and maintaining them will cost less, and will utilize more automation possibilities. Also, MBT takes a systematic route to test generation; this allows for a more goal-oriented and direct approach in achieving...
Model-Based Simulation of Surge and Active Controller Design of an Industrial Centrifugal Compressor applied in Gas Compression Systems, M.Sc. Thesis Sharif University of Technology ; Ghofrani, Mohammad Bagher
Efforts to model and control surge, as the underlying instability of centrifugal compressors, were conducted. Of the three major instabilities in compressors, namely chokage, stall and surge, the latter has a significant role in limiting the available range of operation in centrifugal compressors, which are the most common devices for the transportation of Natural gas. The customary method to circumvent surge, which if occurred, could impose severe, catastrophic and irreversible damages to the machine, is to avoid the zones in which it is likely to develop by means of a recycling system. These often called "surge avoidance" or "surge prevention" schemes have the benefit of high reliability,...
M.Sc. Thesis Sharif University of Technology ; Hosseini, Vahid ; Saidi, Mohammad Hassan
Electronic engine control unit (ECU) operates the different actuators using information signals received from the different sensors. Also in the case of any fault in the sensors and actuators operation ECU is responsible to detect and alert the accruing faults. Most of the common faults in the engine such as leakage in intake system and ignition system are not detectable by ECU, on the other hand ECU fault codes some times are hard to interpret or misleading. So fault diagnosis is usually based on experience of repair staff, and might be time consuming and inaccurate. In this study, using the knowledge of premixed fuel injection SI engines and emission generation and statistical data,...
M.Sc. Thesis Sharif University of Technology ; Behzad , Mehdi ; Hoviattalab, Maryam
The purpose of this project is fault diagnosis of anti-lock brake system with mechatronic approach. To do this, first an appropriate model of the system has been developed. After validating the model, the effects of change in some parameters that indicates the occurrence of a fault in the system are used to examine the behavior of the system in a model-based manner. With this method, it can be analyzed that how a specific fault will impact other system parameters. in fact; the effect of various defects in the system can be detected.
To do this, four common faults such as fault occurrence in hydraulic pump and solenoid valves, air presence and oil leakage in the system are implemented...
To do this, four common faults such as fault occurrence in hydraulic pump and solenoid valves, air presence and oil leakage in the system are implemented...
M.Sc. Thesis Sharif University of Technology ; Alasti, Aria ; Salarieh, Hassan
Fault detection in swarm robots is one of the most important issues that has drawn a lot of scientists’ attention. Previous studies have shown a lot of problems regarding this issue, such as dependency of data-based methods to mission and high complexity of model-based methods on the condition that nonlinear models are used. Extended information filter is an applicable method for fault detection because it could turn the inverse of a big matrix to a simple summation of information that is so desired in terms of calculations. The goal of this study is to identify the agents with fault in swarm robots online by modifying the extended information filter. In this study, it has been attempted to...
M.Sc. Thesis Sharif University of Technology ; Ejtehadi, Mohammad Reza
Molecule of DNA is one of the most important biomolecule in cell which contains genetic information to supply the required proteins for body. Evidence shows prefered binding sequence for proteins exist to interact with proteins which this preference is determined not only by specefic chemical interactions between DNA and protein, but also specific suitable geometrical arrangements of DNA have important role to inding DNA oligomer and protein, such as winding DNA around histon to creating nucleosome is related to curvature and deformability of DNA. Thus knowing elastic behaviour and properties of DNA helps us to approach the answer of such questions. Despite the recent dvancement in labratory...
Article IET Computer Vision ; Volume 8, Issue 1 , Pages 54-65 , 2014 , p. 54-65 ; ISSN: 17519632 ; Kasaei, S ; Sharif University of Technology
Although the ability to estimate the face pose and recognise its identity are common human abilities, they are still a challenge in computer vision context. In this study, the authors aim to overcome these difficulties by learning a non-linear tensorbased model based on multi-linear decomposition. Proposed model maps the high-dimensional image space into low-dimensional pose manifold. For preserving the actual distance along the manifold shape, a graph-based distance measure is proposed. Also, to compensate for the limited number of training poses, mirrored images are added to training ones to improve the recognition accuracy. For performance evaluation of the proposed method, experiments...
Article Proceedings of the American Control Conference ; 2013 , Pages 4417-4422 ; 07431619 (ISSN) ; 9781479901777 (ISBN) ; Shahbakhti, M ; Hedrick, J. K ; Sharif University of Technology
Reduction of cold start hydrocarbon (HC) emission requires a proper compromise between low engine-out HC emission and fast light-off of the three way catalytic converter (TWC). In this paper a model based approach is used to design and optimize a hybrid switching system for reducing HC emission of a mid-sized passenger car during the cold start phase of FTP-75. This hybrid system takes the benefit of increasing TWC temperature during the early stages of the driving cycle by switching between different operational modes. The switching times are optimized to reduce the cumulative tailpipe HC emission of an experimentally validated automotive emission model. It is shown that the new hybrid...
An optimization-based method for prediction of lumbar spine segmental kinematics from the measurements of thorax and pelvic kinematics, Article International Journal for Numerical Methods in Biomedical Engineering ; July , 2015 , Volume 31, Issue 12 ; 20407939 (ISSN) ; Arjmand, N ; Bazrgari, B ; Sharif University of Technology
Given measurement difficulties, earlier modeling studies have often used some constant ratios to predict lumbar segmental kinematics from measurements of total lumbar kinematics. Recent imaging studies suggested distribution of lumbar kinematics across its vertebrae changes with trunk rotation, lumbar posture, and presence of load. An optimization-based method is presented and validated in this study to predict segmental kinematics from measured total lumbar kinematics. Specifically, a kinematics-driven biomechanical model of the spine is used in a heuristic optimization procedure to obtain a set of segmental kinematics that, when prescribed to the model, were associated with the minimum...
Article 2020 IEEE International Conference on Acoustics, Speech, and Signal Processing, ICASSP 2020, 4 May 2020 through 8 May 2020 ; Volume 2020 , May , 2020 , Pages 4032-4036 ; Babaie Zadeh, M ; Jutten, C ; The Institute of Electrical and Electronics Engineers, Signal Processing Society ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc 2020
This work aims to propose an approach for pruning a bagging ensemble regression (BER) model based on sparse representation, which we call sparse representation pruning (SRP). Firstly, a BER model with a specific number of subensembles should be trained. Then, the BER model is pruned by our sparse representation idea. For this type of regression problems, pruning means to remove the subensembles that do not have a significant effect on prediction of the output. The pruning problem is casted as a sparse representation problem, which will be solved by orthogonal matching pursuit (OMP) algorithm. Experiments show that the pruned BER with only 20% of the initial subensembles has a better...