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Garmabaki, Amir SoleimaniORCID iD iconorcid.org/0000-0003-2976-5229
Alternative names
Publications (10 of 45) Show all publications
Esmaeili Kelishomi, A., Garmabaki, A. S., Bahaghighat, M. & Dong, J. (2019). Mobile User Indoor-Outdoor Detection Through Physical Daily Activities. Sensors (3), Article ID 511.
Open this publication in new window or tab >>Mobile User Indoor-Outdoor Detection Through Physical Daily Activities
2019 (English)In: Sensors, ISSN 1424-8220, E-ISSN 1424-8220, no 3, article id 511Article in journal (Refereed) Published
Abstract [en]

An automatic, fast, and accurate switching method between Global Positioning System and indoor positioning systems is crucial to achieve current user positioning, which is essential information for a variety of services installed on smart devices, e.g., location-based services (LBS), healthcare monitoring components, and seamless indoor/outdoor navigation and localization (SNAL). In this study, we proposed an approach to accurately detect the indoor/outdoor environment according to six different daily activities of users including walk, skip, jog, stay, climbing stairs up and down. We select a number of features for each activity and then apply ensemble learning methods such as Random Forest, and AdaBoost to classify the environment types. Extensive model evaluations and feature analysis indicate that the system can achieve a high detection rate with good adaptation for environment recognition. Empirical evaluation of the proposed method has been verified on the HASC-2016 public dataset, and results show 99% accuracy to detect environment types. The proposed method relies only on the daily life activities data and does not need any external facilities such as the signal cell tower or Wi-Fi access points. This implies the applicability of the proposed method for the upper layer applications.

Place, publisher, year, edition, pages
MDPI, 2019
Keywords
sensor-based indoor-outdoor detection, location-based services, human daily activity, smartphone motion sensors, machine learning, context awareness
National Category
Other Civil Engineering
Research subject
Operation and Maintenance
Identifiers
urn:nbn:se:ltu:diva-72799 (URN)10.3390/s19030511 (DOI)000459941200074 ()2-s2.0-85060629071 (Scopus ID)
Note

Validerad;2019;Nivå 2;2019-02-06 (svasva)

Available from: 2019-02-06 Created: 2019-02-06 Last updated: 2019-04-11Bibliographically approved
Soltanali, H., Garmabaki, A. S., Thaduri, A., Parida, A., Kumar, U. & Rohani, A. (2019). Sustainable production process: An application of reliability, availability, and maintainability methodologies in automotive manufacturing. Journal of Risk and Reliability, 233(4), 682-697
Open this publication in new window or tab >>Sustainable production process: An application of reliability, availability, and maintainability methodologies in automotive manufacturing
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2019 (English)In: Journal of Risk and Reliability, ISSN 1748-006X, E-ISSN 1748-0078, Vol. 233, no 4, p. 682-697Article in journal (Refereed) Published
Abstract [en]

Automotive manufacturing industries are required to improve their productivity with higher production rates at the lowest cost, less number of unexpected shutdowns, and reliable operation. In order to achieve the above objectives, the application of reliability, availability, and maintainability methodologies can constitute for resilient operation, identifying the bottlenecks of manufacturing process and optimization of maintenance actions. In this article, we propose a framework for reliability, availability, and maintainability evaluation and maintenance optimization to improve the performance of conveying process of vehicle body in an automotive assembly line. The results of reliability, availability, and maintainability analysis showed that the reliability and maintainability of forklift and loading equipment are the main bottlenecks. To find the optimal maintenance intervals of each unit, a multi-attribute utility theory is applied for multi-criteria decision model considering reliability, availability, and costs. Due to the series configuration of conveying process in automotive assembly line, the optimized time intervals are obtained using opportunistic maintenance strategy. The results could be useful to improve operational performance and sustainability of the production process.

Place, publisher, year, edition, pages
Sage Publications, 2019
Keywords
Automotive manufacturing, conveying process, opportunistic maintenance, reliability, availability, and maintainability methodologies, multi-attribute utility theory
National Category
Reliability and Maintenance Other Civil Engineering
Research subject
Operation and Maintenance
Identifiers
urn:nbn:se:ltu:diva-72427 (URN)10.1177/1748006X18818266 (DOI)000478598600015 ()2-s2.0-85059945405 (Scopus ID)
Note

Validerad;2019;Nivå 2;2019-08-28 (johcin)

Available from: 2019-01-02 Created: 2019-01-02 Last updated: 2019-08-28Bibliographically approved
Garmabaki, A. S., Marklund, S., Thaduri, A., Hedström, A. & Kumar, U. (2019). Underground pipelines and railway infrastructure: failure consequences and restrictions. Structure and Infrastructure Engineering
Open this publication in new window or tab >>Underground pipelines and railway infrastructure: failure consequences and restrictions
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2019 (English)In: Structure and Infrastructure Engineering, ISSN 1573-2479, E-ISSN 1744-8980Article in journal (Refereed) Epub ahead of print
Abstract [en]

Underground pipelines are an essential part of the transportation infrastructure. The structural deterioration of pipelines crossing railways and their subsequent failures can entail critical consequences for society and industry, resulting in direct and indirect costs for all the stakeholders involved. Therefore, continuous and accurate condition assessment is critical for the effective management and maintenance of pipeline networks within the transportation infrastructure. The aim of this study has been to identify failure modes and consequences related to pipelines crossing railway corridors. Expert opinions have been collected through interviews and two sets of questionnaires have been distributed to the 291 municipalities in Sweden, with 137 responses in total. The failure analysis has revealed that pipe deformation has the highest impact, followed by pipe rupture at locations where pipelines cross railway infrastructure. For underground pipelines under railway infrastructure, ageing and the external load were awarded a higher ranking than other potential causes of pipeline failure.

Place, publisher, year, edition, pages
Taylor & Francis, 2019
Keywords
Pipes, pipelines, renovation, maintenance, inspection, maintenance debt, life cycle costs, failure modes, axial loads, pipeline-railway crossings
National Category
Water Engineering Other Civil Engineering
Research subject
Operation and Maintenance; Urban Water Engineering
Identifiers
urn:nbn:se:ltu:diva-76283 (URN)10.1080/15732479.2019.1666885 (DOI)000487636800001 ()
Available from: 2019-10-08 Created: 2019-10-08 Last updated: 2019-10-10
Calle Cordón, Á., Jiménez-Redondo, N., Morales-Gámiz, J., García-Villena, F. A., Peralta-Escalante, J., Garmabaki, A., . . . Morgado, J. (2018). Combined RAMS and LCC analysis in railway and road transport infrastructures. In: Proceedings of 7th Transport Research Arena TRA: . Paper presented at 7th Transport Research Arena TRA 2018, Vienna, 16 – 19 April 2018. Vienna, Austria
Open this publication in new window or tab >>Combined RAMS and LCC analysis in railway and road transport infrastructures
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2018 (English)In: Proceedings of 7th Transport Research Arena TRA, Vienna, Austria, 2018Conference paper, Published paper (Refereed)
Abstract [en]

Life-cycle cost (LCC) analysis is an assessment technique used to evaluate costs incurred during the life-cycle of a system to help in long term decision making. In railway and road transport infrastructures, costs are subject to numerous uncertainties associated to the operation and maintenance phase. By integrating in the LCC the stochastic nature of failure using Reliability, Maintainability, Availability and Safety (RAMS) analyses, maintenance costs can be more reliably estimated. This paper presents an innovative approach for a combined RAMS&LCC methodology for linear transport infrastructures which has been developed under the H2020 project INFRALERT. Results of the application of such methodology in two real use cases are shown, one for rail and another one for road. The use cases show how the approach is implemented in practice.

Place, publisher, year, edition, pages
Vienna, Austria: , 2018
Keywords
intelligent maintenance, linear transport infrastructure, RAMS, Life-Cycle Cost, maintenance
National Category
Reliability and Maintenance Other Civil Engineering
Research subject
Sustainable transportation (AERI); Operation and Maintenance
Identifiers
urn:nbn:se:ltu:diva-65941 (URN)
Conference
7th Transport Research Arena TRA 2018, Vienna, 16 – 19 April 2018
Funder
EU, Horizon 2020, SEP-210181906
Note

Life-cycle cost (LCC) analysis is an assessment technique used to evaluate costs incurred during the life-cycle of a system to help in long term decision making. In railway and road transport infrastructures, costs are subject to numerous uncertainties associated to the operation and maintenance phase. By integrating in the LCC the stochastic nature of failure using Reliability, Maintainability, Availability and Safety (RAMS) analyses, maintenance costs can be more reliably estimated. This paper presents an innovative approach for a combined RAMS&LCC methodology for linear transport infrastructures which has been developed under the H2020 project INFRALERT. Results of the application of such methodology in two real use cases are shown, one for rail and another one for road. The use cases show how the approach is implemented in practice.

Available from: 2017-10-03 Created: 2017-10-03 Last updated: 2018-06-25Bibliographically approved
Mahmood, Y. A., Garmabaki, A., Ahmadi, A. & Verma, A. K. (2018). Reliability model for frequency converter in electrified railway. International Journal of Electrical Power & Energy Systems, 94, 385-392
Open this publication in new window or tab >>Reliability model for frequency converter in electrified railway
2018 (English)In: International Journal of Electrical Power & Energy Systems, ISSN 0142-0615, E-ISSN 1879-3517, Vol. 94, p. 385-392Article in journal (Refereed) Published
Abstract [en]

Reliability analysis of frequency converters based on failures and outages reports constitute an important basis for asset performance and management. Two- and four-state reliability models that recognize the operating characteristics of base load units and peaking units are presented and compared in this study. In this study, a four-state model is modified to a three-state model by combining the ‘needed’ and ‘not-needed’ forced-out states. Moreover, the transitions in the three-state model for power frequency converter have been designed according to real operational data. An outage-reporting database modelled considering IEEE STD 762 is presented and compared with the existing failure-reporting database of the case considered here. Furthermore, a method to extract information missing in the failure-reporting database by electrical readings is proposed to meet the requirements of the outage-reporting database. The study found that the results of indexes based on the IEEE four-state model are not reasonable for the frequency converter given their differences with the gas-turbine results under operational conditions. The forced outage rates and availability factors of twelve actual traction frequency converters of Swedish railways network are presented to validate the modified model.

Place, publisher, year, edition, pages
Elsevier, 2018
Keywords
Outage-data reporting system, Unit state reliability model, IEEE STD 762, Frequency converter
National Category
Reliability and Maintenance Other Civil Engineering
Research subject
Operation and Maintenance
Identifiers
urn:nbn:se:ltu:diva-65173 (URN)10.1016/j.ijepes.2017.08.002 (DOI)000412610000035 ()2-s2.0-85027709160 (Scopus ID)
Note

Validerad;2017;Nivå 2;2017-08-17 (rokbeg)

Available from: 2017-08-17 Created: 2017-08-17 Last updated: 2018-05-07Bibliographically approved
Ahmadi, M., Seneviratne, D. & Garmabaki, A. (2017). An approach to Symbolic Modelling: a Railway Case study for Maintenance Recovery Level Identification. In: Diego Galar, Dammika Seneviratne (Ed.), Proceedings of MPMM 2016: 6th International Conference on Maintenance Performance Measurement and Management, 28 November 2016, Luleå, Sweden. Paper presented at Maintenance Performance and Measurement and Management 2016(MPMM 2016). November 28, Luleå, Sweden (pp. 187-). Luleå: Luleå tekniska universitet
Open this publication in new window or tab >>An approach to Symbolic Modelling: a Railway Case study for Maintenance Recovery Level Identification
2017 (English)In: Proceedings of MPMM 2016: 6th International Conference on Maintenance Performance Measurement and Management, 28 November 2016, Luleå, Sweden / [ed] Diego Galar, Dammika Seneviratne, Luleå: Luleå tekniska universitet, 2017, p. 187-Conference paper, Oral presentation with published abstract (Refereed)
Abstract [en]

Increasing demand for quality and reliability of the asset is progressively seen as a motivation for improved maintenance procedure and management. Always the role of qualitative maintenance data is neglected in the maintenance recovery level identification. Human factor parameter in the maintenance and qualitative technical data, for instance, maintenance experience, maintenance knowledge, training, quality before maintenance, number of previous maintenance, maintenance documentation and environmental condition can be collected and evaluated to increase the accuracy of maintenance recovery estimation. This information always expressed linguistically and considering their effect in the recovery model is challenging. The aim of this study is to propose a symbolic model to capture the effect of above qualitative factor on maintenance recovery level. Fuzzy inference systems are applied to qualitative expert knowledge to extract the percentage effect which can be incorporated in the recovery level model. The tamping railway case study is considered to validate the model. The results show that the maintenance experience and environmental condition are playing main role in maintenance quality. The application of above method can be extended to asset condition assessment in combination with data driven and physical model

Place, publisher, year, edition, pages
Luleå: Luleå tekniska universitet, 2017
National Category
Other Civil Engineering
Research subject
Operation and Maintenance
Identifiers
urn:nbn:se:ltu:diva-63920 (URN)978-91-7583-841-0 (ISBN)
Conference
Maintenance Performance and Measurement and Management 2016(MPMM 2016). November 28, Luleå, Sweden
Available from: 2017-06-12 Created: 2017-06-12 Last updated: 2018-05-07Bibliographically approved
Garmabaki, A., Seneviratne, D., Ahmadi, M., Barabadi, A. & Kumar, U. (2017). Data driven RUL estimation of rolling stock using intelligent functional test (ed.). In: (Ed.), Walls L.,Revie M.,Bedford T (Ed.), Risk, Reliability and Safety: Innovating Theory and Practice - Proceedings of the 26th European Safety and Reliability Conference, ESREL 2016. Paper presented at European Safety and Reliability Conference : European Safety and Reliability Conference 25/09/2016 - 29/09/2016 (pp. 1994-1999). London: CRC Press
Open this publication in new window or tab >>Data driven RUL estimation of rolling stock using intelligent functional test
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2017 (English)In: Risk, Reliability and Safety: Innovating Theory and Practice - Proceedings of the 26th European Safety and Reliability Conference, ESREL 2016 / [ed] Walls L.,Revie M.,Bedford T, London: CRC Press, 2017, p. 1994-1999Conference paper, Published paper (Refereed)
Abstract [en]

The rolling stock health condition is important for both passenger and freight trains in terms of safety, availability, punctuality and efficiency. Various inspection and maintenance methodologies are per-formed on rolling stock equipment to fulfill the above performance measures. This paper suggests a new approach, namely, intelligent functional test (IFTest) to estimate the remaining useful life (RUL) of the equipment, sub-systems and systems of rolling stock dynamically by data driven methods. IFTest generates a baseline of the current operational abilities in contrast to the required abilities. The test integrates the historical and new set of data to track the trend of degradation of equipment. With this approach, the operation and maintenance personnel have ample time to make decisions for the maintenance and failure consequences. In addition, it is supposed that by using such data we are achieving a more accurate result for the estimation of reliability and RUL of critical rolling stock equipment.

Place, publisher, year, edition, pages
London: CRC Press, 2017
Keywords
railway maintenance, rolling stock, intelligent functional test, Data driven model, remaining useful life, reliability, maintenance, Maintenance Decision, Information technology - Computer science, Informationsteknik - Datorvetenskap
National Category
Other Civil Engineering
Research subject
Operation and Maintenance
Identifiers
urn:nbn:se:ltu:diva-26886 (URN)000414164700284 ()2-s2.0-85016201542 (Scopus ID)02558a39-945b-4c38-8fe2-3993f0afd7a1 (Local ID)9781138029972 (ISBN)978-1-315-37498-7 (ISBN)02558a39-945b-4c38-8fe2-3993f0afd7a1 (Archive number)02558a39-945b-4c38-8fe2-3993f0afd7a1 (OAI)
Conference
European Safety and Reliability Conference : European Safety and Reliability Conference 25/09/2016 - 29/09/2016
Note

Upprättat; 2016; 20160617 (amigar)

Available from: 2016-09-30 Created: 2016-09-30 Last updated: 2018-05-07Bibliographically approved
Aliyari, M., Barabadi, A., Barababadi, R. & Garmabaki, A. (2017). Failure and repair data analysis of power distribution systems: a case study (ed.). In: (Ed.), Walls L.,Revie M.,Bedford T (Ed.), Risk, Reliability and Safety: Innovating Theory and Practice - Proceedings of the 26th European Safety and Reliability Conference, ESREL 2016. Paper presented at European Safety and Reliability Conference (ESREL 2016), Glasgow, 25/09/2016 - 29/09/2016 (pp. 2046-2053). London: CRC Press
Open this publication in new window or tab >>Failure and repair data analysis of power distribution systems: a case study
2017 (English)In: Risk, Reliability and Safety: Innovating Theory and Practice - Proceedings of the 26th European Safety and Reliability Conference, ESREL 2016 / [ed] Walls L.,Revie M.,Bedford T, London: CRC Press, 2017, p. 2046-2053Conference paper, Published paper (Refereed)
Abstract [en]

The basic function of electricity distribution system is to supply electrical energy as economically as possible to customer in different geographic with an accept-able level of reliability and quality [1]. The quality of electricity means the supplied current and voltage waveforms are essentially pure sinusoidal waveforms. By incorporating reliability and maintainability con-siderations in the system design and in the planning of system expansion, operation and maintenance the both quality and safety can be improved [2]. To obtain useful results from system reliability assessments, accurate values of component reliability parameters need to be estimated. If the outage database are collected properly, they can reflecting the conditions in which a component works. Hence, collecting, extraction and exploitation useful information from historical data getting more and more importance. A statistical significance of an outage database depends on the quality and reliability as well as number of records data in the database. Such database would describe the real conditions of network equipment more accurately. This study will exploit unplanned outages in electrical components of low voltage (LV) distribution systems in North Khorasan Electricity Distribution Company (NKEDC). The database containing 64035 outages and 150569 Kwh undistributed energy and total time of 2637430 minutes of outages in LV components from July 2010 to February 2016. Here, the main aim of the analysis is to identify the “Significant Few” failures as well as the current maintainability performance of each identified failure models in the power distribution. Such analysis will give a picture of current situation of the system. To start the analysis two meeting have been conducted with the expertise of company to identified the main failure model in the system. Thereafter, the collect data have been explored. The collected data are very detailed regarding the repair time. However, the recorded failure model and preliminary failure cause are not well collected in database. Moreover, we noticed that cause of the failure are not recorded using appropriate coding system that make extracting the data very difficult. Hence, at the first step appropriate coding system have been developed. In this stage, the required recommendation for improving the data collection have been provide and discussed with the company. Based on failure mechanism, of equipment and expert opinions 23 failure mode have been identified and then maintainability for these identified failure mode have been calculated. The trend test and the serial correlation test should all collected repair data are iid distributed and lognormal distribution is suitable tools to model the most identified failure modes

Place, publisher, year, edition, pages
London: CRC Press, 2017
National Category
Other Civil Engineering
Research subject
Operation and Maintenance
Identifiers
urn:nbn:se:ltu:diva-62934 (URN)000414164700291 ()2-s2.0-85016211272 (Scopus ID)978-1-138-02997-2 (ISBN)978-1-315-37498-7 (ISBN)
Conference
European Safety and Reliability Conference (ESREL 2016), Glasgow, 25/09/2016 - 29/09/2016
Available from: 2017-04-07 Created: 2017-04-07 Last updated: 2018-05-07Bibliographically approved
Calle-Cordón, Á., Jiménez-Redondo, N., Morales-Gámiz, F. J., García-Villena, F., Garmabaki, A. & Odelius, J. (2017). Integration of RAMS in LCC analysis for linear transportinfrastructures: A case study for railways. Paper presented at BESTInfra 2017, Czech Technical University, Prague, Czech Republic, September 21-22 2017. IOP Conference Series: Materials Science and Engineering, 236
Open this publication in new window or tab >>Integration of RAMS in LCC analysis for linear transportinfrastructures: A case study for railways
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2017 (English)In: IOP Conference Series: Materials Science and Engineering, ISSN 1757-8981, E-ISSN 1757-899X, Vol. 236Article in journal (Refereed) Published
Abstract [en]

Life-cycle cost (LCC) analysis is an economic technique used to assess the totalcosts associated with the lifetime of a system in order to support decision making in long termstrategic planning. For complex systems, such as railway and road infrastructures, the cost ofmaintenance plays an important role in the LCC analysis. Costs associated with maintenanceinterventions can be more reliably estimated by integrating the probabilistic nature of thefailures associated to these interventions in the LCC models. Reliability, Maintainability,Availability and Safety (RAMS) parameters describe the maintenance needs of an asset in aquantitative way by using probabilistic information extracted from registered maintenanceactivities. Therefore, the integration of RAMS in the LCC analysis allows obtaining reliablepredictions of system maintenance costs and the dependencies of these costs with specific costdrivers through sensitivity analyses. This paper presents an innovative approach for acombined RAMS & LCC methodology for railway and road transport infrastructures beingdeveloped under the on-going H2020 project INFRALERT. Such RAMS & LCC analysisprovides relevant probabilistic information to be used for condition and risk-based planning ofmaintenance activities as well as for decision support in long term strategic investmentplanning.

Place, publisher, year, edition, pages
Institute of Physics (IOP), 2017
National Category
Reliability and Maintenance Other Civil Engineering
Research subject
Operation and Maintenance; Traffic Engineering; Sustainable transportation (AERI)
Identifiers
urn:nbn:se:ltu:diva-65561 (URN)10.1088/1757-899X/236/1/012106 (DOI)000417428700106 ()
Conference
BESTInfra 2017, Czech Technical University, Prague, Czech Republic, September 21-22 2017
Projects
INFRALERT
Funder
EU, Horizon 2020, 636496
Note

2018-01-09 (andbra);Konferensartikel i tidskrift;Bibliografisk uppgift: This research was carried out within the INFRALERT project. This project has received funding fromthe EU Horizon 2020 research and innovation programme under grant agreement No 636496. Theauthors also thank Trafikverket for providing the data in the case study analysis.

Available from: 2017-09-11 Created: 2017-09-11 Last updated: 2018-11-16Bibliographically approved
Ramezani, Z., Pourdarvish, A., Garmabaki, A. & Kapur, P. K. (2017). Optimal Reliability Equivalence Factor for Reliability System improvement Using Memetic Algorithm. International Journal of Reliability, Quality and Safety Engineering (IJRQSE), 24(6), Article ID 1740008.
Open this publication in new window or tab >>Optimal Reliability Equivalence Factor for Reliability System improvement Using Memetic Algorithm
2017 (English)In: International Journal of Reliability, Quality and Safety Engineering (IJRQSE), ISSN 0218-5393, Vol. 24, no 6, article id 1740008Article in journal (Refereed) Published
Abstract [en]

In this paper, optimal reduction and redundancy methods for reliability system improvement have been proposed. Multilevel redundancy allocation problem (MLRAP) based on hot and cold redundancies have been considered. For various reasons, for instance, space limitation, high cost and so on, redundancy method cannot always be applied to improve system reliability. Hence the concept of equivalence has been presented to choice a more suitable method. In these conditions, optimal reduction method has been applied instead of optimal redundancy method. So that we decide what appropriate degree to decrease the failure rate is. To solve this problem, the value of optimal reliability equivalence factor is obtained by equating two obtained reliability functions based on optimal redundancy and reduction methods. Result shows that equivalence value maximizes the efficiency of the system performance in reduction method instead of redundancy method. Finally, the numerical examples illustrate the results obtained theoretically.

Place, publisher, year, edition, pages
World Scientific, 2017
Keywords
Redundancy allocation, Reduction method, Optimal reliability equivalence factor, Memetic algorithm, Multi-level series system
National Category
Reliability and Maintenance Other Civil Engineering
Research subject
Operation and Maintenance
Identifiers
urn:nbn:se:ltu:diva-65560 (URN)10.1142/S0218539317400083 (DOI)2-s2.0-85029160364 (Scopus ID)
Note

Validerad;2017;Nivå 2;2017-09-12 (andbra)

Available from: 2017-09-11 Created: 2017-09-11 Last updated: 2018-12-14Bibliographically approved
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ORCID iD: ORCID iD iconorcid.org/0000-0003-2976-5229

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