| 1. |
- Ahmadzadeh, Farzaneh
(författare)
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Ranking of Two Multi Criteria Decision Making Cases with Evidential Reasoning under Uncertainty
- 2017
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Ingår i: Advances in Science, Technology and Engineering Systems Journal V2(3) ASTESJ-V2(3). - Sweden : ASTES Journal. - 2415-6698. ; 2:3, s. 1059-1063
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Tidskriftsartikel (refereegranskat)abstract
- Many decision problems have more than one objective that need to be dealt with simultaneously. Moreover, because of the qualitative nature of the most of real world problem it is an inevitable activity and very important to interpret and present the uncertain information for making effective decision. The Evidential Reasoning (ER) approach which is one of the latest development within multi criteria decision making (MCDM) seems to be the best fit to synthesize both qualitative and quantitative data under uncertainty. To support this claim, two case studies were tested to illustrate the application of ER for prioritization and ranking of decision alternative to support decision process even with uncertain information. The overall goal of the first case study is to identify and prioritize factors that can be considered maintenance-related waste within the automotive manufacturing industry. The result after applying ER shows “inadequate resources” and “weather /indoor climate,” respectively, are the highest and lowest average scores for creating maintenance-related waste. This prioritization methodology can be used as a tool to create awareness for managers seeking to reduce or eliminate maintenance-related waste. The aim of the second case study is to look at the possibility of having a new approach for sustainable design. So through a literature review six design strategies were taken into consideration in order to develop a new approach based on all advantages (sustainable factors) of the six approaches. For ranking and finding out about the most important factors the evidential reasoning (ER) approach is used. Based on ER all the important factors, apart from the one collected from interviews are a part of eco-design. So it means among all strategies eco-design is the most dominant strategy in term of environment. However two of the important factors are not found in any strategy but in interviews. These factors can be used as the building blocks for a new approach. The importance of having a better structured decision process is essential for the success of any organization, so it can be applied widely in most of real world problem dealing with making effective decision.
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| 2. |
- Amirpour, Sepideh, 1980, et al.
(författare)
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Improving of Heat Spreading in a SiC Propulsion Inverter using Graphene Assembled Films
- 2021
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Ingår i: Advances in Science, Technology and Engineering Systems Journal. - : ASTES Journal. - 2415-6698. ; 6:6, s. 98-111
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Tidskriftsartikel (refereegranskat)abstract
- The focus of this work is first to establish the effect of the chip temperature and thermal feedback on the determination of the power loss in a three-phase propulsion inverter, then to demonstrate the possibility of achieving an improved heat spreading through the different layers inside a SiC power module by using graphene assembled films in the packaging of the power module. The power loss analysis has been carried out for two Silicon Carbide (SiC) modules in a vehicle inverter, incorporating the MOSFET’s reverse conduction as well as including the impact of blanking time on the inverter on-state losses. This data for calculating the losses is determined at an operationg situation below the filed weakening speed with a high torque for a PMSM machine The operating point is found to be the worst operating condition point when looking at the power loss point. First, it can be noted that not accounting for the thermal feed-back, the power loss is considerably underrated, i.e.,11-15% on the on-state converter. Following, the analysis of utilizing the graphene layer in the SiC module reveals a reduction of 10°C per SiC chips in the junction temperature of the SiC MOSFET is achievable. The reduction is calculated based on an applied power loss per SiC chips in steady-state simulation. Furthermore, up to 15°C decrease in the transient computation over the Worldwide Harmonized Light Vehicles Test Cycle (WLTC) per SiC chip is noticed. Moreover, a reduction up to 50% for the junction to case thermal resistance (Rth,JC) is observed by adding the graphene layer in the power module.
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| 3. |
- Cordeiro, Cheryl Marie, 1975
(författare)
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Which User of technology? Perspectivising the UTAUT model by application of the SFL language Pronoun System towards a systems perspective of technology acceptance and use
- 2018
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Ingår i: ASTESJ Advances in Science, Technology and Engineering Systems Journal. - : ASTES Journal. - 2415-6698. ; 3:2, s. 309-318
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Tidskriftsartikel (refereegranskat)abstract
- This study applies systemic functional linguistics (SFL) as complementary framework of analysis of technology acceptance models (TAMs). The purpose is to bridge research methodology language in international business (IB) studies and engineering management science. Currently TAMs and its consolidated version, the Unified Theory of Acceptance and Use of Technology (UTAUT) provides for a typology of one user in one context scenario. The need for the UTAUT model to account for multiple users in multiple work contexts in a single framework of analysis was foregrounded in the study of the workflow processes of a remote services business model of a European founded multinational business enterprise (MBE) with regards to its (i) intra-firm improvements in managing remote services cases, and its (ii) extra-firm selling of life cycle management remote services contracts. The Enterprise has global operations in over 100 countries, of which this study focused on its European operations of improving the quality of remote services for the marine industry. Through an application of SFL unto UTAUT, this study illustrates how multiple users in multiple contexts can be analysed simultaneously, and whose behaviours can be accounted for in a single framework of analysis. The combined SFL UTAUT model addresses the initial statisticity of the UTAUT model, whilst at the same time, expands upon current theoretical perspectives of technology use and acceptance that can be applied in practice.
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| 4. |
- Li, Zheng, et al.
(författare)
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Two-stage performance engineering of container-based virtualization
- 2018
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Ingår i: Advances in Science, Technology and Engineering Systems Journal. - : ASTES Journal. - 2415-6698. ; 3:1, s. 521-536
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Tidskriftsartikel (refereegranskat)abstract
- Cloud computing has become a compelling paradigm built on compute and storage virtualization technologies. The current virtualization solution in the Cloud widely relies on hypervisor-based technologies. Given the recent booming of the container ecosystem, the container-based virtualization starts receiving more attention for being a promising alternative. Although the container technologies are generally considered to be lightweight, no virtualization solution is ideally resource-free, and the corresponding performance overheads will lead to negative impacts on the quality of Cloud services. To facilitate understanding container technologies from the performance engineering's perspective, we conducted two-stage performance investigations into Docker containers as a concrete example. At the first stage, we used a physical machine with “just-enough” resource as a baseline to investigate the performance overhead of a standalone Docker container against a standalone virtual machine (VM). With findings contrary to the related work, our evaluation results show that the virtualization's performance overhead could vary not only on a feature-by-feature basis but also on a job-to-job basis. Moreover, the hypervisor-based technology does not come with higher performance overhead in every case. For example, Docker containers particularly exhibit lower QoS in terms of storage transaction speed. At the ongoing second stage, we employed a physical machine with “fair-enough” resource to implement a container-based MapReduce application and try to optimize its performance. In fact, this machine failed in affording VM-based MapReduce clusters in the same scale. The performance tuning results show that the effects of different optimization strategies could largely be related to the data characteristics. For example, LZO compression can bring the most significant performance improvement when dealing with text data in our case.
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| 5. |
- Lindén, Johannes, 1993-, et al.
(författare)
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Productify news article classification model with Sagemaker
- 2020
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Ingår i: Advances in Science, Technology and Engineering Systems. - : ASTES Journal. - 2415-6698. ; 5:2, s. 13-18
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Tidskriftsartikel (refereegranskat)abstract
- News companies have a need to automate and make the process of writing about popular and new events more effective. Current technologies involve robotic programs that fill in values in templates and website listeners that notify editors when changes are made so that the editor can read up on the source change on the actual website. Editors can provide news faster and better if directly provided with abstracts of the external sources and categorical meta-data that supports what the text is about. To make categorical meta-data a reality an auto-categorization model was created and optimized for Swedish articles written by local news journalists. The problem was that it was not scale-able enough to use out of the box. Instead of having this local model that could make good predictions of the text documents, the model is to be deployed in the cloud and an API interface is created. The API can be accessed from the tools where the articles is being written and therefore these services can automatically assign categories to the articles once the journalist is done writing it. To allow scale-ability to several thousands of simultaneously categorized articles and at the same time improving the workflow of deploying new models easier the API is uploaded to Sagemaker where several models are trained and once an improved model is found that model will be used in production in such a way that the system organically adapts to new written articles. An evaluation of Sagemaker API was done and it was concluded that the complexity of this solution was polynomial.
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| 6. |
- Mumtaz, Majid, et al.
(författare)
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Strong authentication protocol based on Java crypto chip as a secure element
- 2016
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Ingår i: Advances in Science, Technology and Engineering Systems. - : ASTES Journal. - 2415-6698. ; 1:5, s. 21-26
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Tidskriftsartikel (refereegranskat)abstract
- Smart electronic devices and gadgets and their applications are becoming more and more popular. Most of those devices and their applications handle personal, financial, medical and other sensitive data that require security and privacy protection. In this paper we describe one aspect of such protection – user authentication protocol based on the use of X.509 certificates. The system uses Public Key Infrastructure (PKI), challenge/response protocol, mobile proxy servers, and Java cards with crypto capabilities used as a Secure Element. Innovative design of the protocol, its implementation, and evaluation results are described. In addition to end-user authentication, the described solution also supports the use of X.509 certificates for additional security services – confidentiality, integrity, and non-repudiation of transactions and data in an open network environment. The system uses Application Programming Interfaces (APIs) to access Java cards functions and credentials that can be used as add-ons to enhance any mobile application with security features and services.
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| 7. |
- Pasha, Shahab, et al.
(författare)
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Distributed microphone arrays, emerging speech and audio signal processing platforms : A review
- 2020
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Ingår i: Advances in Science, Technology and Engineering Systems. - : ASTES Journal. - 2415-6698. ; 5:4, s. 331-343
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Tidskriftsartikel (refereegranskat)abstract
- Given ubiquitous digital devices with recording capability, distributed microphone arrays are emerging recording tools for hands-free communications and spontaneous tele-conferencings. However, the analysis of signals recorded with diverse sampling rates, time delays, and qualities by distributed microphone arrays is not straightforward and entails important considerations. The crucial challenges include the unknown/changeable geometry of distributed arrays, asynchronous recording, sampling rate mismatch, and gain inconsistency. Researchers have recently proposed solutions to these problems for applications such as source localization and dereverberation, though there is less literature on real-time practical issues. This article reviews recent research on distributed signal processing techniques and applications. New applications benefitting from the wide coverage of distributed microphones are reviewed and their limitations are discussed. This survey does not cover partially or fully connected wireless acoustic sensor networks.
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| 8. |
- Paul, Satyam, 1981-, et al.
(författare)
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Recent Advances in Intelligent-Based Structural Health Monitoring of Civil Structures
- 2018
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Ingår i: Advances in Science, Technology and Engineering Systems Journal (ASTESJ). - : Advances in Science, Technology and Engineering Systems Journal. - 2415-6698. ; 3:5, s. 339-353
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Forskningsöversikt (refereegranskat)abstract
- This survey paper deals with the structural health monitoring systems on the basis of methodologies involving intelligent techniques. The intelligent techniques are the most popular tools for damage identification in terms of high accuracy, reliable nature and the involvement of low cost. In this critical survey, a thorough analysis of various intelligent techniques is carried out considering the cases involved in civil structures. The importance and utilization of various intelligent tools to be mention as the concept of fuzzy logic, the technique of genetic algorithm, the methodology of neural network techniques, as well as the approaches of hybrid methods for the monitoring of the structural health of civil structures are illustrated in a sequential manner.
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| 9. |
- Valieva, Inna, 1985-, et al.
(författare)
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Multiple machine learning algorithms comparison for modulation type classification based on instantaneous values of the time domain signal and time series statistics derived from wavelet transform
- 2021
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Ingår i: Advances in Science, Technology and Engineering Systems. - : ASTES Publishers. - 2415-6698. ; 6:1, s. 658-671
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Tidskriftsartikel (refereegranskat)abstract
- Modulation type classification is a part of waveform estimation required to employ spectrum sharing scenarios like dynamic spectrum access that allow more efficient spectrum utilization. In this work multiple classification features, feature extraction, and classification algorithms for modulation type classification have been studied and compared in terms of classification speed and accuracy to suggest the optimal algorithm for deployment on our target application hardware. The training and validation of the machine learning classifiers have been performed using artificial data. The possibility to use instantaneous values of the time domain signal has shown acceptable performance for the binary classification between BPSK and 2FSK: Both ensemble boosted trees with 30 decision trees learners trained using AdaBoost sampling and fine decision trees have shown optimal performance in terms of both an average classification accuracy (86.3 % and 86.0 %) and classification speed (120 0000 objects per second) for additive white gaussian noise (AWGN) channel with signal-to-noise ratio (SNR) ranging between 1 and 30 dB. However, for the classification between five modulation classes demonstrated average classification accuracy has reached only 78.1 % in validation. Statistical features: Mean, Standard Deviation, Kurtosis, Skewness, Median Absolute Deviation, Root-Mean-Square level, Zero Crossing Rate, Interquartile Range and 75th Percentile derived from the wavelet transform of the received signal observed during 100 and 500 microseconds were studied using fractional factorial design to determine the features with the highest effect on the response variables: classification accuracy and speed for the additive white gaussian noise and Rician line of sight multipath channel. The highest classification speed of 170 000 objects/second and 100 % classification accuracy has been demonstrated by fine decision trees using as an input Kurtosis derived from the wavelet coefficients derived from signal observed during 100 microseconds for AWGN channel. For the line of sight fading Rician channel with AWGN demonstrated classification speed is slower 130 000 objects/s.
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