| 1. |
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| 2. |
- Singh, Dhirendra Pratap, et al.
(författare)
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Co-supplementation of isomalto-oligosaccharides potentiates metabolic health benefits of polyphenol-rich cranberry extract in high fat diet-fed mice via enhanced gut butyrate production
- 2018
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Ingår i: European Journal of Nutrition. - : Springer Science and Business Media LLC. - 1436-6207 .- 1436-6215. ; 57:8, s. 2897-2911
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Tidskriftsartikel (refereegranskat)abstract
- Purpose Cranberries are a rich source of polyphenolic antioxidants. Purified sugars or artificial sweeteners are being added to cranberry-based food products to mask tartness. Refined sugar and artificial sweeteners intake modulate gut microbiota and result in metabolic complications. We evaluated effects of isomalto-oligosaccharides (IMOs; sweet tasting non-digestible oligosaccharides) with cranberry extract (CRX) on high fat diet (HFD)-induced metabolic alterations in mice. Methods Male Swiss albino mice were fed normal chow or HFD (58% fat kcal), and were administered either CRX (200 mg/kg) alone or in combination with IMOs (1 g/kg). Cecal short-chain fatty acids, abundances of selected (1) butyrate producing, (2) metabolically beneficial, and (3) selective lipopolysaccharides producing gram negative gut bacteria were studied. Further, gut-related histological, biochemical, genomic changes along with circulating pro-/anti-inflammatory markers and systemic obesity-associated metabolic changes were studied. Results Co-supplementation of CRX and IMOs significantly improved cecal SCFAs, especially butyrate levels, selected butyrate-producing bacteria (clostridial cluster XIVa bacteria) and butyrate kinase expression in HFD-fed mice. The combination also significantly improved gut beneficial bacterial abundance, gut histology and related changes (colon mucin production, gut permeability) as compared to individual agents. It also prevented HFD-induced systemic and tissue inflammation, glucose intolerance and systemic obesity-associated metabolic changes in adipose tissue and liver. The combination of CRX and IMOs appeared more effective in the prevention of HFD-induced gut derangements. Conclusion Combination of CRX and IMOs could be advantageous for normalization of metabolic alterations seen in diet-induced obesity via beneficial modulation of gastrointestinal health.
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| 3. |
- Kumar, Amarjeet, et al.
(författare)
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Development of Novel Hybrid Models for Prediction of Drought-and Stress-Tolerance Indices in Teosinte Introgressed Maize Lines Using Artificial Intelligence Techniques
- 2022
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Ingår i: Sustainability. - : MDPI. - 2071-1050. ; 14:4
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Tidskriftsartikel (refereegranskat)abstract
- Maize (Zea mays subsp. mays) is a staple food crop in the world. Drought is one of the most common abiotic challenges that maize faces when it comes to growth, development, and production. Further knowledge of drought tolerance could aid with maize production. However, there has been less study focused on investigating in depth the drought tolerance of inbred maize lines using artificial intelligence techniques. In this study, multi-layer perceptron (MLP), support vector machine (SVM), genetic algorithm-based multi-layer perceptron (MLP-GA), and genetic algorithm-based support vector machine (SVM-GA) hybrid artificial intelligence algorithms were used for the prediction of drought tolerance and stress tolerance indices in teosinte maize lines. Correspondingly, the gamma test technique was applied to determine efficient input and output vectors. The potential of the developed models was evaluated based on statistical indices and graphical representations. The results of the gamma test based on the least value of gamma and standard error indices show that days of anthesis (DOA), days of silking (DOS), yield index (YI), and gross yield per plant (GYP) information vector arrangements were determined to be an efficient information vector combination for the drought-tolerance index (DTI) as well as the stress-tolerance index (STI). The MLP, SVM, MLP-GA, and SVM-GA algorithms’ results were compared based on statistical indices and visual interpretations that have satisfactorily predict the drought-tolerance index and stress-tolerance index in maize crops. The genetic algorithm-based hybrid models (MLP-GA and SVM-GA) were found to better predict the drought-tolerance index and stress-tolerance index in maize crops. Similarly, the SVM-GA model was found to have the highest potential to forecast the DTI and STI in maize crops, compared to the MLP, SVM, and MLP-GA models.
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| 4. |
- Bengtsson, Lars, et al.
(författare)
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Circulation and Mixing in Ice-Covered Lakes
- 2011
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Ingår i: Encyclopedia of Snow, Ice and Glaciers. - Dordrecht : Springer Netherlands. - 904812641X ; Part 3, s. 139-141
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Bokkapitel (övrigt vetenskapligt/konstnärligt)
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| 5. |
- Bengtsson, Lars, et al.
(författare)
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Direct Surface Runoff
- 2011
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Ingår i: Encyclopedia of Snow, Ice and Glaciers. - Dordrecht : Springer Netherlands. - 904812641X ; Part 4, s. 232-234
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Bokkapitel (övrigt vetenskapligt/konstnärligt)
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| 6. |
- Bengtsson, Lars, et al.
(författare)
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Ice Covered Lakes
- 2011
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Ingår i: Encyclopedia of Snow, Ice and Glaciers. - Dordrecht : Springer Netherlands. - 904812641X ; Part 9, s. 589-590
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Bokkapitel (övrigt vetenskapligt/konstnärligt)
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| 7. |
- Bengtsson, Lars, et al.
(författare)
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Snowmelt and groundwater or base flow
- 2011
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Ingår i: Encyclopedia of Snow, Ice and Glaciers. - Dordrecht : Springer Netherlands. - 9789048126415 ; , s. 91-93
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Bokkapitel (övrigt vetenskapligt/konstnärligt)
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| 8. |
- Bengtsson, Lars, et al.
(författare)
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Urban Snow
- 2011
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Ingår i: Encyclopedia of Snow, Ice and Glaciers. - Dordrecht : Springer Netherlands. - 904812641X ; Part 20, s. 1211-1217
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Bokkapitel (övrigt vetenskapligt/konstnärligt)
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| 9. |
- Shastri, Anish, et al.
(författare)
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On the Implementation of LMS-based Algorithm for Increasing the Lifetime of IoT Networks
- 2018
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Ingår i: 2018 IEEE International Conference on Advanced Networks and Telecommunications Systems (ANTS). - : IEEE.
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Konferensbidrag (refereegranskat)abstract
- This paper focuses on the customized-wireless sensor node implementation of the classical least mean square (LMS) algorithm for the reduction in data-transmissions from the sensor nodes to the sink in internet of things (IoT) networks. This reduction, in turn, increases the battery life of the sensor node. The system was deployed in outdoor and indoor environments to read the ambient temperature and then perform the prediction of the sensed data in order to minimize the number of data-transmissions to the sink node. The utility of the proposed concept has been demonstrated using the measured data and the battery life is increased 2.64 and 2.53 times in indoor and outdoor environments, respectively.
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| 10. |
- Singh, Ashutosh, et al.
(författare)
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Taxonomy of cryptic species in theCyornis rubeculoidescomplex in the Indian subcontinent
- 2020
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Ingår i: Ibis. - : WILEY. - 0019-1019 .- 1474-919X. ; 162:3, s. 924-935
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Tidskriftsartikel (refereegranskat)abstract
- Taxa classified as subspecies may in fact be cryptic species. We assessed the taxonomic status of the Blue-throated FlycatcherCyornis rubeculoidescomplex in India, which consists of several forms with similar plumages and song. We used mitochondrial and nuclearDNA, plumage traits, and detailed song analysis to ascertain the taxonomic status of the different forms. The molecular data identified three primary clades: (1) in the west Himalayan foothills, (2) at higher elevations in the northeast hill states of Meghalaya, Nagaland and Mizoram, and (3) at lower elevations in the northeastern hills of Meghalaya and the east Himalayas of Arunachal Pradesh. The western clade represents nominateC. rubeculoides rubeculoides. The high-elevation eastern clade was considered to beC. rubeculoides rogersi, because it included a sample from this subspecies from near the type locality in southwest Myanmar. These two sister clades had an estimated divergence time of 1.5 million years (my). The low-elevation east clade has previously been assigned toC. rubeculoides, but we showed it is closely related to the Hainan Blue FlycatcherCyornis hainanus, formerly thought to breed only further east, with an estimated divergence time of only ~0.8 my. This clade may represent a subspecies ofC. hainanusor, given reports of widespread sympatry withC. hainanusin Thailand, a distinct species,Cyornis dialilaemus. However, more research is advocated, including molecular data, from the area of overlap. Songs were remarkably similar across all taxa. In playback experiments,C. r. rubeculoidesin the west responded to all taxa. This is in agreement with recent work demonstrating that song differences and responses to songs are not always a good indicator of the progress of reproductive isolation.
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| 11. |
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| 12. |
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| 13. |
- Fadeev, Andrey, et al.
(författare)
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ALKALs are in vivo ligands for ALK family receptor tyrosine kinases in the neural crest and derived cells
- 2018
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Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - : National Academy of Sciences. - 0027-8424 .- 1091-6490. ; 115:4, s. E630-E638
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Tidskriftsartikel (refereegranskat)abstract
- Mutations in anaplastic lymphoma kinase (ALK) are implicated in somatic and familial neuroblastoma, a pediatric tumor of neural crest-derived tissues. Recently, biochemical analyses have identified secreted small ALKAL proteins (FAM150, AUG) as potential ligands for human ALK and the related leukocyte tyrosine kinase (LTK). In the zebrafish Danio rerio, DrLtk, which is similar to human ALK in sequence and domain structure, controls the development of iridophores, neural crest-derived pigment cells. Hence, the zebrafish system allows studying Alk/Ltk and Alkals involvement in neural crest regulation in vivo. Using zebrafish pigment pattern formation, Drosophila eye patterning, and cell culture-based assays, we show that zebrafish Alkals potently activate zebrafish Ltk and human ALK driving downstream signaling events. Overexpression of the three DrAlkals cause ectopic iridophore development, whereas loss-of-function alleles lead to spatially distinct patterns of iridophore loss in zebrafish larvae and adults. alkal loss-of-function triple mutants completely lack iridophores and are larval lethal as is the case for ltk null mutants. Our results provide in vivo evidence of (i) activation of ALK/LTK family receptors by ALKALs and (ii) an involvement of these ligand-receptor complexes in neural crest development.
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| 14. |
- Ghaffari, Mona, et al.
(författare)
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Music Oh my Music : A Network Perspective on Online Music Listening Behaviour
- 2020
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Konferensbidrag (refereegranskat)abstract
- The success of online music platforms depends on the strength of the recommendation systems (RSs) that employ users’ interaction data to offer customised music listening experiences. Traditional recommendation systems, however, assume users are independent actors and identically distributed, ignoring social interactions or connections among users and the role of the Network Effect (NE). In this study, leveraging the social network theory and utilising the attributes of an online music platform, we investigate the impact of network effect on the patterns of music listening. As a result, we propose a new approach for measuring the network effect (Universal Network Effect) as a function of the structure of the network, data-driven learning, and improvements realised with Artificial Intelligence (AI), to scrutinize network effect at both individual and whole network level. The everevolving approach to network effect measurement enables us to further the study to determine the changes in user behaviour.
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| 15. |
- Horng, Ray-Hua, et al.
(författare)
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Growth mechanism and characteristics of beta-Ga2O3 heteroepitaxailly grown on sapphire by metalorganic chemical vapor deposition
- 2022
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Ingår i: Materials Today Advances. - : ELSEVIER. - 2590-0498. ; 16
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Tidskriftsartikel (refereegranskat)abstract
- In this study, monoclinic gallium oxide (beta-Ga2O3) epilayer was successfully grown on c-plane, (0001), sapphire substrate by metalorganic chemical vapor deposition (MOCVD) with interplaying growth temperature, TEGa flow rate, and growth time. X-ray diffraction 20 scans show only three narrow diffraction peaks referred to beta-Ga2O3 ((2) over bar 01), ((4) over bar 02), and ((6) over bar 03) in all epilayers, indicating a superior crystalline quality. Current-voltage (I-V) measurement reveals that these beta-Ga2O3 films are insulating and exhibit high resistance in a range of 10(12)-10(14) Omega. The crystallization characteristics of the epilayers can be effectively improved with thickness through increasing TEGa flow rate and growth time, which was evidenced by X-ray rocking curves and I-V measurements. However, the surface roughness of beta-Ga2O3 film increases with growth time and TEGa flow rate. When the growth temperature increases above 825 degrees C, the thickness of beta-Ga2O3 film decreases clearly. Furthermore, it can be found that the growth rate decreased as the growth time increasing. The growth mechanism based on first-principles calculation was proposed as that 3D growth induced by the lattice mismatch between beta-Ga2O3 and sapphire starts at nucleation stage, and follows up a lateral growth promoting a 2D growth after the thick epilayer being grown. In addition, the complex chemical reaction between TEGa and oxygen precursors was unraveled by density function theory calculation. (c) 2022 Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (http:// creativecommons.org/licenses/by-nc-nd/4.0/).
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| 16. |
- Horng, Ray-Hua, et al.
(författare)
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Ion implantation effects on the characteristics of 8-Ga2O3 epilayers grown on sapphire by MOCVD
- 2022
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Ingår i: Ceramics International. - : ELSEVIER SCI LTD. - 0272-8842 .- 1873-3956. ; 48:24, s. 36425-36432
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Tidskriftsartikel (refereegranskat)abstract
- In this study, the Si-ions implantation technique with different doses from 1 x 1014 to 1 x 1015 cm-2 and dose energy 30, 40 and 50 keV was used to tune the electrical properties in unintentionally doped (UID) 8-Ga2O3 epilayers grown on the sapphire substrates by metalorganic chemical vapor deposition (MOCVD). A high quality UID 8-Ga2O3 epilayers were fabricated using the optimized growth parameters of MOCVD. The UID and Si-ions implanted 8-Ga2O3 epilayers were examined and results were compared with the help of X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy, and transmission electron microscopy. Si-ions implantation parameters were also simulated by stopping and range of ions in matter software (SRIM) and actual Si-ions concentration was measured by secondary ions mass spectroscopy. The electrical properties of the implanted 8-Ga2O3 epilayers were measured by transmission length method and Hall measurements. The sheet resistivity for the 8-Ga2O3epilayers with Si-ion dose of 1 x 1014, 6 x 1014 and 1 x 1015 cm-2 were found as 2.047, 0.158 and 0.144 Cd cm, respectively measured by Hall measurements and the electron carrier concentrations for the above doses were 4.39 x 1018, 6.86 x 1018 and 7.98 x 1019 cm-3. From the above results, the ion implantation was demonstrated to effectively reduce the resistivity with the high carrier concentrations.
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| 17. |
- Huang, Tianqi, et al.
(författare)
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Failure Characterization of Discrete SiC MOSFETs under Forward Power Cycling Test
- 2024
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Ingår i: Energies. - : MDPI AG. - 1996-1073. ; 17:11
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Tidskriftsartikel (refereegranskat)abstract
- Silicon carbide (SiC)-based metal-oxide-semiconductor field-effect transistors (MOSFETs) hold promising application prospects in future high-capacity high-power converters due to their excellent electrothermal characteristics. However, as nascent power electronic devices, their long-term operational reliability lacks sufficient field data. The power cycling test is an important experimental method to assess packaging-related reliability. In order to obtain data closest to actual working conditions, forward power cycling is utilized to carry out SiC MOSFET degradation experiments. Due to the wide bandgap characteristics of SiC MOSFETs, the short-term drift of the threshold voltage is much more serious than that of silicon (Si)-based devices. Therefore, an offline threshold voltage measurement circuit is implemented during power cycling tests to minimize errors arising from this short-term drift. Different characterizations are performed based on power cycling tests, focused on measuring the on-state resistance, thermal impedance, and threshold voltage of the devices. The findings reveal that the primary failure mode under forward power cycling tests, with a maximum junction temperature of 130 degrees C, is bond-wire degradation. Conversely, the solder layer and gate oxide exhibit minimal degradation tendencies under these conditions.
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| 18. |
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| 19. |
- Silvander, Johan, et al.
(författare)
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Validating Trust in Human Decisions to Improve Expert Models Based on Small Data Sets
- 2023
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Ingår i: Business Modeling and Software Design. - : Springer Nature. - 9783031367571 ; , s. 256-267
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Konferensbidrag (refereegranskat)abstract
- When a model is built based on expert knowledge, a small data set will, in many cases, form the base for the model. It must be possible to validate the trustworthiness and model improvement potential of the provided information from humans or machines. In this study, we have investigated how to evaluate the information from humans to improve the model itself. We used evaluation research and collected the research data with the help of focus group interviews and questionnaires. The result of the study suggests a way to determine the trustworthiness of answers from humans and how to understand if these answers indicate a change to the underlying expert model. The introduction of divergence, and candidate areas, made it possible to evaluate the trustworthiness and changes to the expert model. These were deemed valuable by practitioners.
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| 20. |
- Singh, Akhilendra Pratap, et al.
(författare)
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Introduction to Advanced Combustion Techniques and Engine Technologies for Automotive Sector
- 2020
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Ingår i: Energy, Environment, and Sustainability. - Singapore : Springer Singapore. - 2522-8374 .- 2522-8366. ; , s. 3-6
-
Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- To resolve the transportation sector issues such as rapidly increasing petroleum consumption and stringent emission norms for vehicles, researchers have proposed three solution strategies namely advanced combustion techniques, after-treatment systems and alternative fuels. This book covers all three aspects for automotive sector. A dedicated section of this book is based on methanol, which discusses about the methanol utilization strategies in vehicles, especially in two wheelers. Second section of this book is based on advanced combustion techniques, which includes gasoline compression ignition (GCI), gasoline direct injection (GDI), and spark assisted compression ignition (SACI). Fourth section is based on emissions and after treatments systems. Last section of this book includes two different aspects. First is the vehicle lightweighting and second is the development of UAVs for defence applications. Overall this book emphasizes on different techniques, which can improve engine efficiency and reduce harmful emissions for a sustainable transport system.
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| 21. |
- Singh, Bhanu Pratap, et al.
(författare)
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Analysis of the Thermo-mechanical Performance of Double-Sided Cooled Power Modules
- 2024
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Ingår i: 2024 25th International Conference on Thermal, Mechanical and Multi-Physics Simulation and Experiments in Microelectronics and Microsystems, EuroSimE 2024. - : Institute of Electrical and Electronics Engineers (IEEE).
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Konferensbidrag (refereegranskat)abstract
- Double-sided cooled (DSC) power semiconductor modules have garnered increased interest over the past decade due to their ability to offer an additional path for heat removal, facilitating higher power density operation while reducing junction temperatures and thermal stresses. Nevertheless, when operating at similar junction temperatures, DSC modules might exhibit elevated thermo-mechanical stress compared to single-sided cooled (SSC) modules. This increase can be attributed to restricted vertical movement within the DSC modules. Furthermore, the integration of various spacers within the DSC modules, which enable bond wire connections to gate terminals, can significantly influence both the thermal performance and induced thermo-mechanical stresses. Depending on the materials used in the spacer, the thermal performance and thermo-mechanical stresses inside the module can vary. In this study, we have first analysed the thermal performance of the DSC power modules employing different spacers. Following that, we have also performed thermo-mechanical analysis in different solder layers. Finally, fatigue analysis is done to demonstrate the weakest solder layer inside the package.
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| 22. |
- Singh, Bhanu Pratap, et al.
(författare)
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Analyzing the Impact of Die Positions inside the Power Module on the Reliability of Solder Layers for Different Power Cycling Scenarios
- 2023
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Ingår i: 2023 24th International Conference on Thermal, Mechanical and Multi-Physics Simulation and Experiments in Microelectronics and Microsystems, EuroSimE 2023. - : Institute of Electrical and Electronics Engineers (IEEE).
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Konferensbidrag (refereegranskat)abstract
- Solder layers, used as bonding material inside the power module to attach the semiconductor die on Direct Bond Copper (DBC) substrate and DBC substrate on baseplate, are one of the regions most prone to failure. The failure usually occurs in the form of solder cracks and depends on various operating conditions, such as-maximum temperature, temperature swing, and heating time. The cracks generated inside the solder layers can eventually result in its delamination. Power modules are usually power cycled to estimate the failure sites and mechanisms. However, the failure mechanisms can vary depending on the frequency, amplitude, and range of the temperature in the Power Cycling Tests (PCT). In this study, we have used the Finite Element Method (FEM) in COMSOL Multiphysics to analyse the impact of the PCT on both die attach, and baseplate attach solder layers. Additionally, the effect of the degree of asymmetry in the die position on the reliability of both the solder layers are analysed. The FEA (Finite Element Analysis) results are analysed to have a better understanding about the aspects impacting the lifetime of the power module.
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| 23. |
- Singh, Ravindra Pratap, et al.
(författare)
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Smart Nanomaterials for Biosensors, Biochips and Molecular Bioelectronics
- 2012. - 1
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Ingår i: Smart Nanomaterials for Sensor Application. - USA : Bentham eBooks. - 9781608052417 ; , s. 3-41
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- The domain of biology has greatly been benefited by advances in other sciences leading to new levels of sensitivity, precision and resolution in biomolecular detection. The key driving force is the complementary length scale between biological structures that range from the 10's of nanometers (proteins, DNA, viruses) to the micron scale (cells and cellular assemblies) and capabilities of nanosystems to manipulate and control such feature sizes within our environment. Progress and development in biosensor development will inevitably focus upon the technology of the nanomaterials that promise to solve the biocompatibility and biofouling problems. The biosensors are integrated with new technologies in molecular biology, micro-fluidics, and smart nanomaterials, have applications in agricultural production, food processing, and environmental monitoring for rapid, specific, sensitive, inexpensive, in-field, on-line and/or real-time detection of pesticides, antibiotics, pathogens, toxins, proteins, microbes, plants, animals, foods, soil, air, and water. Thus, biosensors are excellent analytical tools for pollution monitoring, by which implementation of legislative provisions to safeguard our biosphere could be made effectively plausible. The current trends and challenges with smart nanomaterials for various applications have been the focuse in this chapter that pertains to biosensor development, bionanoelectronics, nanotechnology, biotechnology and miniaturization. All these growing areas will have a remarkable influence on the development of new ultra biosensing devices to resolve the severe pollution problems in the future that not only challenge the human health but also affect adversely other various comforts to living entities.
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| 24. |
- Singh, Shailesh Pratap, 1976-, et al.
(författare)
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From Traditional to Next Generation AAA: A reference Architecture for a dedicated IoT Network
- 2019
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Ingår i: Proceedings of the IV International Scientific Conference “Convergent Cognitive Information Technologies”.
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Konferensbidrag (refereegranskat)abstract
- Emerging scenarios for the “Internet of Things” (IoT) require a dedicated software defined network over the conventional communication network provided by the different service providers and free to use communication methodologies. These IoT networks have their own dedicated requirements, based on the different stakeholders involved in it, which can be realized via dynamic context-based authentication, authorization and accounting (AAA). This AAA needs to be envisaged in a much larger perspective than the current perspective in telecom networks. As part of this study, we have identified a few external stakeholders, who are domain and IoT experts and discussed the various requirements, scenarios and change scenarios for the dedicated IoT networks. Relying on Zachman’s framework, a reference architecture that we call as “Smart AAA agent for dedicated IoT network” is presented to the domain experts and evaluated against their scenarios utilizing a scenario-based software architecture analysis method. The scenarios discussed and utilized for the analysis encompass two ends of the IoT spectrum of requirements. The medical domain scenarios have critical IoT perspective as lives and health of patients is involved, while the enterprise IoT scenarios involve huge scalability and monetizability aspect, which is very important for the industry. With this reference architecture, we demonstrate a system capable of providing a software defined network fulfilling the requirements of a dedicated IoT network as enlisted in scenarios by the external stakeholders. Furthermore, this proposed reference architecture is evaluated with a software architect and matured to its current state and made available for any future research, development or standardization for 5G and next generation networks for the Internet of Things.
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| 25. |
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| 26. |
- Singh, Shailesh Pratap, 1976-, et al.
(författare)
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Smart and Adaptive Architecture for a Dedicated Internet of Things Network Comprised of Diverse Entities : A Proposal and Evaluation
- 2022
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Ingår i: Sensors. - : MDPI. - 1424-8220. ; 22:8
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Tidskriftsartikel (refereegranskat)abstract
- Advances in 5G and the Internet of Things (IoT) have to cater to the diverse and varying needs of different stakeholders, devices, sensors, applications, networks, and access technologies that come together for a dedicated IoT network for a synergistic purpose. Therefore, there is a need for a solution that can assimilate the various requirements and policies to dynamically and intelligently orchestrate them in the dedicated IoT network. Thus we identify and describe a representative industry-relevant use case for such a smart and adaptive environment through interviews with experts from a leading telecommunication vendor. We further propose and evaluate candidate architectures to achieve dynamic and intelligent orchestration in such a smart environment using a systematic approach for architecture design and by engaging six senior domain and IoT experts. The candidate architecture with an adaptive and intelligent element (“Smart AAA agent”) was found superior for modifiability, scalability, and performance in the assessments. This architecture also explores the enhanced role of authentication, authorization, and accounting (AAA) and makes the base for complete orchestration. The results indicate that the proposed architecture can meet the requirements for a dedicated IoT network, which may be used in further research or as a reference for industry solutions. © 2022 by the authors. Licensee MDPI, Basel, Switzerland.
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| 27. |
- Singh, Shailesh Pratap, 1976-
(författare)
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System Architectures and Trade-offs for an Internet of Things Network
- 2023
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The emerging scenarios and use cases for the Internet of Things (IoT) and the latest developments of 5G and beyond networks envision a connected world with diverse stakeholders as an integral and dynamic part of it. The synergistic coming together of the different stakeholders also brings along with it different values, requirements, and policies that need to be orchestrated in an automated and agile manner. This presents a requirement for a dynamic and context-aware system that can provide the assimilation of the different policies and requirements of the stakeholders and perform a dynamic orchestration in the system. Artificial intelligence has a major role in bringing in the desired adaptability and automation in the context-aware system. Besides, with the advent of fog computing for IoT and multi-access edge computing (MEC) in 5G, the execution location also introduces benefits and challenges bringing along different engineering trade-offs such as for execution performance, maintainability, and usability.This thesis aims at exploring and analyzing the engineering trade-offs of employing (artificial intelligence) AI-based and a static rule-based system for these orchestration requirements. It further explores the engineering trade-offs of employing the proposed systems at a cloud-only or fog setup. Scenarios are taken from different industry experts and evolved further. Different architecture solutions are proposed and a scenario-based architecture assessment is performed. A PERT (Program Evaluation Review Technique) analysis is also performed for the systems and the change scenarios for them. Two prototypes are developed using C++ and an expert system (for AI) and measurements are captured and evaluated for the different scenarios and configurations. The performance trade-offs of the execution of the scenarios on the two prototypes while executing over fog or cloud-only setups are evaluated. Execution performance is measured in terms of the time taken for the execution and a comparative analysis is done with graphs and charts explaining the various execution trade-offs. Maintainability and usability trade-offs are also discussed in the light of the two reference systems executing on the two locations, viz. fog, and cloud. As the next-generation IoT and telecommunication systems have diverse and strict quality of service (QoS) requirements, the challenges of learning in the system are evaluated and discussed in the thesis. Bayesian networks and probabilistic programming are explored and evaluated for validating the input of small data for evolving an existing expert system model.
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