Academic literature on the topic 'Interval type-2 FNN'
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Journal articles on the topic "Interval type-2 FNN"
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Chen, Yong, Kaiyu Niu, and Wei Zhang. "Handover Optimization Algorithm Based on T2RFS-FNN." Computational Intelligence and Neuroscience 2022 (December 14, 2022): 1–10. http://dx.doi.org/10.1155/2022/6293192.
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As a key technology for highly reliable communication in the fifth generation mobile communication for railway (5G-R) high-speed railway wireless communication system, once the handover fails, it will pose a serious risk to the safe operation of high-speed railway. As the speed of high-speed trains continues to increase, the handover will become more frequent, and how to improve the success rate of the handover is a key problem that needs to be solved. In this paper, we proposed an optimization algorithm based on the interval type 2 feature selection recurrent fuzzy neural network (T2RFS-FNN), which is a recurrent fuzzy neural network with interval type 2 feature selection, to address the problem of fixed hysteresis threshold and single consideration for the handover algorithm between the control plane and the user plane of the high-speed railway under 5G-R. The algorithm integrates reference signal receiving power (RSRP). Reference signal receiving quality (RSRQ) and throughput to optimise the hysteresis threshold. First, a feedforward neural network structure is designed to implement fuzzy logic inference, and an interval type-two Gaussian subordination function is used to improve the nonlinear expressiveness of the model. Then, a feature selection layer is added to determine the output of the affiliation function, which completes the optimization of the hysteresis threshold and overcomes the drawback of the fixed hysteresis threshold of the handover algorithm. Finally, simulation analysis of the control-plane and user-plane handover algorithms is carried out separately. The results show that the proposed method can effectively improve the success rate and reduce the ping-pong handover rate compared to the comparison algorithms. The results provide a theoretical reference for the speedup of high-speed railway trains and the evolution of the global system for mobile communications for railway (GSM-R) to 5G-R.
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Li, I.-Hsum, and Lian-Wang Lee. "Interval type 2 hierarchical FNN with the H-infinity condition for MIMO non-affine systems." Applied Soft Computing 12, no. 8 (August 2012): 1996–2011. http://dx.doi.org/10.1016/j.asoc.2012.01.022.
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ZHANG, YING, CHENG-SHAN CAI, and GUO-ZHU ZHAO. "Dictyosporium wuyiense sp. nov. from Wuyi Mountain China." Phytotaxa 314, no. 2 (July 25, 2017): 251. http://dx.doi.org/10.11646/phytotaxa.314.2.6.
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Dictyosporium wuyiense, a new anamorphic fungus collected on a dead branch of bamboo in Tongmugou, Wuyi Mountain, China, is described and illustrated. It is characterised by being cheiroid, septate, complanate, and yellow, with two types of conidia composed mostly of five parallel compact rows of cells, sometimes with variable hyaline apical vesical appendages. Type 1 conidia are longer and the three central rows are protruding with swollen apical cells; type 2 conidia are wider and fan-shaped, with rows of apical cells approximately the same length. The conidial morphology on potato dextrose agar plates was variable, most with 2–3 vesical appendages. In phylogenetic analyses of the internal transcribed spacer (ITS) of rDNA, Dictyosporium wuyiense clustered with most Dictyosporium species in Dictyosporiaceae, but was a distinct species. Both morphological and molecular evidence support its description as a new species. A brief review of Dictyosporium and allied species is provided.
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Li, Guoqi, Lifu Zhu, Yongjun Hu, Yingzi Jin, Toshiaki Setoguchi, and Heuy Dong Kim. "Influence of Chord Lengths of Splitter Blades on Performance of Small Axial Flow Fan." Open Mechanical Engineering Journal 9, no. 1 (June 25, 2015): 361–70. http://dx.doi.org/10.2174/1874155x01509010361.
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On the basis of small axial fan with five blades, 6 types of small axial flow fans with different chord lengths splitter blades were designed. Numerical simulation of 6 fan models with splitter blades and prototype fan were done by using Fluent. Based on the obtained simulation results, internal flow characteristics and aerodynamic noise were analyzed and compared. It indicates that: splitter blades with suitable chord length have improved significantly on internal flow characteristics, which inhibits backflow from pressure surface to the suction surface at blade tip and leading edge and restrains flow separation. The 6 model fans are better than prototype fan on aerodynamic noise improvement, but too long or too short chord lengths are both disadvantage to improve aerodynamic noise. The results reveal that 2/6, 3/6 and 4/6 chord length model have relatively better acoustic characteristics and internal flow characteristics. The research program will offer a reference for structural improvements and noise reduction on small axial flow fan.
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Ratnasari, Nita Yunianti, Putri Halimu Husna, Marni Marni, Susana Nurtanti, and Tantut Susanto. "Adherence to medication behavior among tuberculosis patients and their affecting factors: a cross-sectional study at Public Health Center of Wonogiri District, Indonesia." Frontiers of Nursing 7, no. 3 (October 2, 2020): 279–85. http://dx.doi.org/10.2478/fon-2020-0024.
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AbstractObjectiveThis study aimed to identify the influence of predisposing, enabling, and reinforcing factors and the adherence to medication behavior among tuberculosis patients in Selogiri Wonogiri Public Health Center.MethodsThis study employed a descriptive cross-sectional research design. A questionnaire was used to collect primary data. Secondary data were obtained from patient treatment cards (Form TB 01). This research was carried out at Selogiri Health Center from November to December 2017. The participants were patients, both new and old patients, who had completed their treatment in the last 2 months or more, recorded from January 2016 to December 2017. A total sampling technique was used in this study. Logistic regression analysis was used to analyze the influence of predisposing, enabling, and reinforcing factors and the adherence to medication among tuberculosis patients.ResultsThe results of logistic regression analysis indicated that there were four independent variables that have a significant relationship with treatment variables, namely education (odds ratio (OR) = 0.025; 95% confidence interval (CI) = 0.001–0.039); knowledge (OR = 3.37; 95% CI = 0.19–57.71); type of drug (OR = 0.448; 95% CI = 0.012–16.07), and means of transportation (OR = 25.77; 95% CI = 1.33–500.47).ConclusionsEducation, knowledge, type of drug, and means of transportation influence medication compliance among tuberculosis patients. Therefore, supporting patients during medication program of tuberculosis is needed to improve their adherence medication during multidrug therapy.
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Ishikawa, Takuya, Hiroki Kawashima, Eizaburo Ohno, Hiroki Suhara, Daijuro Hayashi, Takeshi Hiramatsu, Hiroshi Matsubara, et al. "Usefulness of endoscopic ultrasound-guided fine-needle biopsy for the diagnosis of autoimmune pancreatitis using a 22-gauge Franseen needle: a prospective multicenter study." Endoscopy 52, no. 11 (June 24, 2020): 978–85. http://dx.doi.org/10.1055/a-1183-3583.
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Abstract Background Detailed histological evaluation is important in the diagnosis of autoimmune pancreatitis (AIP). However, it remains challenging to obtain adequate tissue from the pancreas. Recently, several reports have suggested the usefulness of endoscopic ultrasound-guided fine-needle biopsy (EUS-FNB) using the new “core” needles for acquiring pancreatic tissue. We aimed to investigate the usefulness of EUS-FNB for diagnosing AIP with one such needle, a 22-gauge Franseen needle. Methods Patients who met the imaging diagnostic criteria for AIP based on the International Consensus Diagnostic Criteria (ICDC) were enrolled in the study. All patients underwent EUS-FNB with a 22-gauge Franseen needle. Histological findings were evaluated based on the ICDC, and the detection rates of level 1 and level 1 or 2 histology were calculated. Results 56 patients from 11 different institutions were enrolled in the final analysis (55 suspected to have type 1 AIP and one with type 2 AIP). Lymphoplasmacytic infiltration, obliterative phlebitis, storiform fibrosis, and > 10 IgG4-positive cells per high-power field were detected in 55 (100 %), 24 (43.6 %), 40 (72.7 %), and 36 (65.5 %) of the 55 patients, respectively. The detection rates of level 1 and level 1 or 2 histology for AIP were 58.2 % (95 % confidence interval [CI] 44.1 % – 71.3 %) and 92.7 % (95 %CI 82.4 % – 98.0 %), respectively, which were apparently higher than our historical results (7.9 % [95 %CI 1.7 % – 21.4 %] and 62.2 % [95 %CI 46.5 % – 76.2 %], respectively) using a conventional needle. Conclusions EUS-FNB with a 22-gauge Franseen needle demonstrated favorable detection rates which would be clinically beneficial for the histological diagnosis of AIP.
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Saaristo, Timo, Leena Moilanen, Jari Jokelainen, Eeva Korpi-Hyövälti, Mauno Vanhala, Juha Saltevo, Leo Niskanen, et al. "Cardiometabolic profile of people screened for high risk of type 2 diabetes in a national diabetes prevention programme (FIN-D2D)." Primary Care Diabetes 4, no. 4 (December 2010): 231–39. http://dx.doi.org/10.1016/j.pcd.2010.05.005.
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BARBOZA, Elzio da Silva, Mauro Cesar GERALDES, Francisco Egídio Cavalcante PINHO, Carlos José FERNANDES, and Carlos Humberto da SILVA. "STRUCTURAL, STRATIGRAPHIC AND METALLOGENETIC ASPECTS OF THE PARAGUAY FOLD AND THRUST BELT: IMPLICATIONS FOR GOLD MINERALIZATION AND COLLAGE OF THE GONDWANA." Geosciences = Geociências 39, no. 2 (July 16, 2020): 279–96. http://dx.doi.org/10.5016/geociencias.v39i2.12699.
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ABSTRACT - Paraguay Belt occupies the western portion of the Tocantins Province, surrounding the Southeast of the Amazonian Craton and the eastern border of the Rio Apa Block, suggesting continuity with Tucavaca Belt in Bolivia. The rocks of the Paraguay belt were initially deposited in a glaciomarine environment in sites proximal to the cratonic area and deeper marine under the influence of turbidite flows in distal sites (Cuiabá Group, Bauxi and Puga Formation). The cap carbonates, thick limestone and dolostone succession of the Araras Group and siltstones and diamictites of the Serra Azul Formation related to Glaskiers glaciation overlay these diamictites (related to Marinoan glaciation). On the top there are terrigenous sediments of the Alto Paraguay Group, represented by sandstones of Raizama and claystones of Diamantino formations, respectively. The belt can be divided into three distinct structural zones: The Internal Domain is comprised of turbidite and glaciogenic sequences. Glaciogenic rocks on the base and carbonaceous and terrigenous sediments on the top occur in the External Domain. Horizontal platformal cover on the Amazonian Craton rocks are characterized by open folds. Structural studies allowed characterization of continuous deformational phases: the main deformational phase generated regional inverse folds with a NE-SW trend and fan geometry. Several regionally widespread lode-type gold deposits related to four types of the quartz veins were identified: type 1 is in concordance to bedding, type 2 is parallel to Sn, type 3 is parallel to Sn+2, and vertical Type 4 (Au-rich) is orthogonal to Sn. Late deformation developed in the Cuiabá region, recorded the closure of the ocean and the invertion where the hydrothermal fluids are the responsible for the orebodies formation.
Keywords: Paraguay Belt, Structural, Stratigraphy, Metalogenesis.
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Tuomilehto, H., M. Peltonen, M. Partinen, J. Seppä, T. Saaristo, E. Korpi-Hyövälti, H. Oksa, et al. "Sleep-disordered breathing is related to an increased risk for type 2 diabetes in middle-aged men, but not in women – the FIN-D2D survey." Diabetes, Obesity and Metabolism 10, no. 6 (June 2008): 468–75. http://dx.doi.org/10.1111/j.1463-1326.2007.00729.x.
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Solovey, Maria A., Ying Wang, Stefan Gattenloehner, Elisabeth Hessmann, Stephan Metzelder, Christian Michel, Volker Ellenrieder, Joachim R. Goethert, Andreas Neubauer, and Andreas Burchert. "Nuclear NFATc1 Causes Development of Fms-like Receptor Tyrosine Kinase 3 Receptor (FLT3) Internal Tandem Duplication Mutation-Positive (FLT3-ITD) Acute Myeloid Leukemia (AML) and Mediates Drug Resistance." Blood 128, no. 22 (December 2, 2016): 1722. http://dx.doi.org/10.1182/blood.v128.22.1722.1722.
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Abstract Background: Although an internal tandem duplication (ITD) of the Fms-like receptor tyrosine kinase 3 receptor (FLT3) confers a very poor prognosis in acute myeloid leukemia (AML), it is insufficient to cause AML, suggesting important cooperating genetic events. NFATc1 is a member of the nuclear factor of activated T-cells (NFAT) transcription factor family, whose activation is dependent on nuclear translocation. NFATc1 is well known for its central role in regulating T-cell development and function, but was also shown to contribute to neoplastic transformation in diverse types of cancers. We have recently demonstrated that NFATc1 is overexpressed in primary FLT3-ITD+ AML causing resistance to the FLT3-kinase inhibitor sorafenib in vitro. Here we asked, whether NFATc1 induces AML transformation and drug resistance when expressed in the context of FLT3-ITD+ in vivo. Methods: Using the stem cell like (SCL)-promoter, Cre-recombinase inducible expression of a constitutively nuclear NFATc1 protein (cnNFATc1) was targeted to the early hematopoietic stem cell compartment. The SCL-Cre/cnNFATc1 mice were subsequently crossed with transgenic FLT3-ITD mice to yield Scl-Cre+/-/cnNFATc1+/+/FLT3-ITD+/+ mice (FCN+/+), which co-express cnNFAT and FLT3-ITD in the stem cell compartment. Results: Whereas FLT3-ITD mice developed a non-lethal, mild myeloproliferative disease, co-expression of FLT3-ITD with cnNFATc1 led to rapidly fatal AML. The median survival of FCN mice was only four months (range, 2 to 8 ). In median, FCN mice had 15-fold (range, 10 to 20) increased white blood cell count, a high proportion of circulating peripheral blasts, severe anemia and thrombocytopenia. There was also a significant B-cell developmental block. As opposed to F+/+ animals, FCN+/+ mice revealed a severe spleno- and hepatomegaly secondary to a gross leukemic infiltration, which disrupted the normal anatomical architecture of the involved organs. Fluorescence activating cell sorting and colony forming unit (CFU) assays demonstrated that cnNFATc1, when expressed in the context of FLT3-ITD, leads to a significant expansion of the lin-Sca+c-kit+ (LSK) stem cell-, progenitor cell (LK)-, the Gr-1-/CD11b+ monocytic and Gr-1low/CD11b+ immature myeloid compartments in bone marrow and spleen. FCN+/+-AML was polyclonal, and re-transplantable in secondary wild-type recipient mice. In vivo, cnNFATc1 caused not only potent FLT3-ITD inhibitor resistance to sorafenib and to the more FLT3-ITD-selective compound quizartinib, but also to chemotherapy. Comparative mRNA-sequencing of sorted LK and LSK compartments in wild-type, F+/+, C+/- N+/+, and FCN+/+ mice will reveal the genetic basis of the biological cooperativity between NFATc1 and FLT3-ITD in stem and progenitor cell compartments. Consistent with the murine data, a data set of AML patients (n=163) revealed that NFATc1 overexpression alone or when combined with FLT3-overexpression was associated with a significantly decreased overall survival (hazard ratio [HR] 1.91, CI 1.29-2.18, p=0.001 versus HR 2.57, CI 1.62-4.08, p<0.0001). Conclusions: These results provide for the first time evidence for an important role of nuclear NFATc1 overexpression in the molecular pathogenesis of FLT3-ITD positive AML and the induction of drug resistance. These data also underscore that the mutational landscape in AML insufficiently describes AML biology. Disclosures No relevant conflicts of interest to declare.
Dissertations / Theses on the topic "Interval type-2 FNN"
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Cheng, Martin Chun-Sheng, and pjcheng@ozemail com au. "Dynamical Near Optimal Training for Interval Type-2 Fuzzy Neural Network (T2FNN) with Genetic Algorithm." Griffith University. School of Microelectronic Engineering, 2003. http://www4.gu.edu.au:8080/adt-root/public/adt-QGU20030722.172812.
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Type-2 fuzzy logic system (FLS) cascaded with neural network, called type-2 fuzzy neural network (T2FNN), is presented in this paper to handle uncertainty with dynamical optimal learning. A T2FNN consists of type-2 fuzzy linguistic process as the antecedent part and the two-layer interval neural network as the consequent part. A general T2FNN is computational intensive due to the complexity of type 2 to type 1 reduction. Therefore the interval T2FNN is adopted in this paper to simplify the computational process. The dynamical optimal training algorithm for the two-layer consequent part of interval T2FNN is first developed. The stable and optimal left and right learning rates for the interval neural network, in the sense of maximum error reduction, can be derived for each iteration in the training process (back propagation). It can also be shown both learning rates can not be both negative. Further, due to variation of the initial MF parameters, i.e. the spread level of uncertain means or deviations of interval Gaussian MFs, the performance of back propagation training process may be affected. To achieve better total performance, a genetic algorithm (GA) is designed to search better-fit spread rate for uncertain means and near optimal learnings for the antecedent part. Several examples are fully illustrated. Excellent results are obtained for the truck backing-up control and the identification of nonlinear system, which yield more improved performance than those using type-1 FNN.
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Cheng, Martin Chun-Sheng. "Dynamical Near Optimal Training for Interval Type-2 Fuzzy Neural Network (T2FNN) with Genetic Algorithm." Thesis, Griffith University, 2003. http://hdl.handle.net/10072/366350.
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Type-2 fuzzy logic system (FLS) cascaded with neural network, called type-2 fuzzy neural network (T2FNN), is presented in this paper to handle uncertainty with dynamical optimal learning. A T2FNN consists of type-2 fuzzy linguistic process as the antecedent part and the two-layer interval neural network as the consequent part. A general T2FNN is computational intensive due to the complexity of type 2 to type 1 reduction. Therefore the interval T2FNN is adopted in this paper to simplify the computational process. The dynamical optimal training algorithm for the two-layer consequent part of interval T2FNN is first developed. The stable and optimal left and right learning rates for the interval neural network, in the sense of maximum error reduction, can be derived for each iteration in the training process (back propagation). It can also be shown both learning rates can not be both negative. Further, due to variation of the initial MF parameters, i.e. the spread level of uncertain means or deviations of interval Gaussian MFs, the performance of back propagation training process may be affected. To achieve better total performance, a genetic algorithm (GA) is designed to search better-fit spread rate for uncertain means and near optimal learnings for the antecedent part. Several examples are fully illustrated. Excellent results are obtained for the truck backing-up control and the identification of nonlinear system, which yield more improved performance than those using type-1 FNN.Thesis (Masters)
Master of Philosophy (MPhil)
School of Microelectronic Engineering
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Hsu, Kang-wei, and 許剛維. "Synchronization of Chaotic Systems by Using Adaptive Interval Type-2 FNN Control." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/80236716087320431296.
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碩士逢甲大學
電子工程所
98
Abstract In this thesis the new indirect adaptive control, direct adaptive control and hybrid adaptive control of interval type-2 fuzzy neural network (FNN) controls for chaos synchronization between two different chaotic systems and chaotic time-delay systems are proposed to handle the training data corrupted by noise or rule uncertainties involving external disturbances. Adaptive interval type-2 fuzzy FNN control scheme and tracking approach are incorporated to synchronize two different chaotic time-delay systems and the effect of the synchronization error via adaptive fuzzy system relies only on the solution of an algebraic Riccati-like matrix equation. The Laypunov stability theorem has been used to testify the asymptotic stability of the chaotic time-delay systems. Moreover, the stability analysis of the proposed control scheme will be guaranteed in the sense that all signals involved are uniformly bounded and arbitrary small attenuation level of the external disturbance on the synchronization error can be achieved. The simulation example is included to confirm validity and performance of the advocated design methodology. Keywords: Direct adaptive control, Indirect adaptive control, Hybrid adaptive control, interval type-2 fuzzy FNN, chaotic system, chaotic synchronization.
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Yang, Ching-Chuan, and 楊景全. "Design and implementation of ducted fan type two-axis control system:using supervisory robust interval type-2 fuzzy logic controller." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/35804399766273015236.
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碩士中原大學
電機工程研究所
98
In this thesis, we design and implementation a ducted fan type two-axis control system. The ducted fan type two-axis control system has many uncertainty and time varying terms that is difficult to establish an exact mathematical model. In order to control such a system, a supervisory robust interval type-2 fuzzy logic controller is developed. The concept of type-2 fuzzy sets (T2FSs) is an extension of the concept of type-1 fuzzy sets (T1FSs) and it is suitable for membership function is difficult to determine when mathematical model of system is not clear. In addition, the stability of supervisory robust interval type-2 fuzzy logic controller can be guaranteed by Lyapunov theory. Finally, the simulation and experimental results of propose ducted fan type two-axis control system demonstrates the good performance of the whole control system.
Book chapters on the topic "Interval type-2 FNN"
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Park, Keon-Jun, Jae-Hyun Kwon, and Yong-Kab Kim. "Design of Interval Type-2 FCM-Based FNN and Genetic Optimization for Pattern Recognition." In Communications in Computer and Information Science, 126–33. Berlin, Heidelberg: Springer Berlin Heidelberg, 2012. http://dx.doi.org/10.1007/978-3-642-35603-2_20.
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Lin, T. C., Ming-Che Chen, and M. Roopaei. "Type-2 Fuzzy Sliding Mode Synchronization." In Chaos Synchronization and Cryptography for Secure Communications, 314–36. IGI Global, 2011. http://dx.doi.org/10.4018/978-1-61520-737-4.ch014.
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This chapter presents an adaptive interval type-2 fuzzy neural network (FNN) controller to synchronize chaotic systems with training data corrupted by noise or rule uncertainties involving external disturbances. Adaptive interval type-2 FNN control scheme and sliding mode approach are incorporated to deal with the synchronization of non-identical chaotic systems. In the meantime, based on the adaptive fuzzy sliding mode control, the Laypunov stability theorem has been used to testify the asymptotic stability of the chaotic systems. The chattering phenomena in the control efforts can be reduced and the stability analysis of the proposed control scheme will be guaranteed in the sense that all the states and signals are uniformly bounded and the external disturbance on the synchronization error can be attenuated. The simulation example is included to confirm validity and performance of the advocated design methodology.
Conference papers on the topic "Interval type-2 FNN"
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Lin, Tsung-Chih, and Kang-Wei Hsu. "Chaos synchronization between two different chaotic systems using adaptive interval type-2 FNN control." In 2010 International Symposium on Computer, Communication, Control and Automation (3CA). IEEE, 2010. http://dx.doi.org/10.1109/3ca.2010.5533754.
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Manikandan, Arumugampillai, and Zeeshan Anwar. "Case Study: Consecutive Failure of Lube Oil Cooler Fans Coupling." In SPE Annual Technical Conference and Exhibition. SPE, 2021. http://dx.doi.org/10.2118/206120-ms.
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Abstract Do we analyze on why can even the most reliable turbomachinery are getting failure and stopped? In some cases, it's all about bad installation or design literally. This paper explores the challenges one site had with repeated failure of lube oil fin fan coolers coupling which caused the unit availability of more than 3 months. It outlines the troubleshooting attempts made to remedy this issue, its root cause, and the resulting solution. This issue occurred at a site with a train configuration of motor driven centrifugal compressors. The plant lube oil system has been configured with 3 trains. Each train has been configured with Main electric motor + Vorecon Gearbox + Low Pressure centrifugal compressor + High Pressure centrifugal compressor. Lube oil system of the train has been configured as 2 lube oil coolers and 2 working oil coolers. Lube oil coolers are having fins with air cooler type. Air is supplied by fin fans and each train has 2 lube oil cooler fans and 2 working oil cooler fans. In total site has 3 trains x 4 fin fans so it has 12 fin fan cooler fans. All cooler fans are driven by electric motor which is coupled with gearbox and gear box is connected with cooler fan. During normal operation of working oil cooler fan A- stopped rotation suddenly from normal operation. During investigation, motor shaft was found running freely. No movement was seen on cooler fan. Coupling between motor to gearbox was inspected. Coupling is shear plate coupling. Its spacer flexible element were found broken into several pieces. Further investigation revealed that motor coupling hub was moving free axially back and forth due to clearance between motor shaft to coupling hub internal diameter. Motor side Coupling hub bolt hole was found with loss of material and ovality in shape. Hub locking Allen screw was found in damaged condition. Missing materials were noted and broken shear plate materials were found around coupling guard area. While site team was conducting the investigation on the unit A, similar incident occurred in next unit and other 3 units with 2 days difference between them. During detailed investigation it has been noted that all motor to gear box coupling are shear plates and shear plates were broken. Coupling hub was found loose and coupling hub locking screw was found broken or partial damage.
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Ji, Wen-Tao, Chuang-Yao Zhao, Qi-Bin Dai, Shu-Heng Han, Ding-Cai Zhang, Ya-Ling He, and Wen-Quan Tao. "Experimental Study of Water Cooled Condenser Made of Three Dimensional and High Fin Density Integral-Finned Tubes." In ASME 2014 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2014. http://dx.doi.org/10.1115/imece2014-39025.
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The thermo-hydraulic performance of two shell and tube condensers was investigated with an experimental approach. The experiment is conducted in a water cooled centrifugal chiller test rig. The condensers are made of three-dimensional (3-D) and high fin density integral-finned (2-D) tubes. 2-D and 3-D tubes all have the diameter of 3/4 inch (19mm). The 2-D tube has external fin density of 56fpi (fins per inch), fin height 1.023mm and 48 internal ribs per circle. The 3-D enhanced tube has the external fin density of 45fpi, fin height of 0.981mm and 45 internal ribs per circle. The 3-D tube is widely used in the water cooled chillers. 2-D tube is a newly designed surface with enhanced external fin density. Condensing heat transfer coefficient of R134a outside single horizontal tube is firstly tested at saturate temperature of 40°C. At the internal water velocity of 2.2m/s, the overall heat transfer coefficients of 2-D tube is in the range of 10364.7 to 12420.9W/m2K, 4.2% ∼ 9.0% higher than 3-D tube. External condensing heat transfer coefficient is 16.3% ∼ 25.2% higher than 3-D tube. The condensers are manufactured with these two types of tubes. Both condensers have the same geometric parameters except the tubes and tube bundle space. The length of tube in the condenser is 4000mm. The tube bundles are arranged in a staggered mode. For the integral-fin tube condenser, the longitudinal tube pitch of tube arrays is 23mm in rows and the transverse is 20mm. At the same power input and cooling water inlet temperature of 32°C, the cooling power of 2-D tube condenser are respectively of 1755.4kW and 1769.4kW; 3-D tube condenser is 1727.5kW and 1770.5kW. The pressure drop increased about 11.2% ∼ 15.9% for the 2-D tube condenser compared with 3-D tube condenser. Generally, the two condensers have the same heat transfer performance, while the integral-fin tube condenser saves 15% of copper material consumption.
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Littera, D., M. Velardi, A. Cozzolini, G. Yoder, M. C. Besch, D. K. Carder, and M. Gautam. "Integrated Physical and Chemical Measurements of PM Emissions of Dispersing Plume Heavy-Duty Diesel Truck: Wind Tunnel Studies: Part I — Design and Commissioning." In ASME 2012 Internal Combustion Engine Division Fall Technical Conference. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/icef2012-92091.
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Over the past few decades there has been considerable progress made in understanding the processes leading to formation and evolution of particulate matter (PM) emissions from heavy duty diesel engines (HDDE). This progress has been primarily made under controlled laboratory conditions with the use of constant volume sampling (CVS) systems and to a limited extend through on-road chase studies. West Virginia University (WVU) is attempting to close the present knowledge gap by conducting detailed experiments in a custom designed and constructed environmental wind tunnel. The understanding and knowledge has recently been further extended to new emission reduction technologies, such as the diesel particulate filter (DPF) which has dramatically changed the size distribution and chemical composition of PM. Additionally, the selective catalytic reduction (SCR) technology has shown to further enhance the formation of nucleation mode particles as well as alter their morphology. Even with advances in technology there remains a considerable gap in the current level of understanding of PM formation and evolution, since the combustion generated PM from diesel engines is not discernible from the atmospheric background PM measured beyond 300m from highways. After being emitted from the vehicle exhaust system, the process of dilution in the atmosphere leads to a multitude of PM transformation phenomena, such as volatilization, coagulation, and condensation. The work presented herein has been divided into two parts which are published separately from each another. The first part describes the design and commissioning process of the wind tunnel focusing on both, aerodynamic and structural constraints, which ultimately led to the definition of the main characteristics of the facility. The resulting design is a subsonic, non-recirculating, suction type tunnel, with a 16ft high and 16ft wide test section capable of housing a full-size heavy-duty tractor cab. A 2,200hp suction fan is employed to provide up to 80 mph wind speeds. The 115ft test cell length guarantees for a 2 second residence time for the exhaust plume evolution (at 35 mph) and complies with turbulence intensity (less than 1%) and quality flow requirement as identified for this type of application. In addition, the West Virginia University (WVU) wind tunnel has been equipped with a custom made sampling system able to move in all three dimensions in order to measure spatially resolved plume characteristics. The second part will describe the actual test procedures and the experimental results and will be published in a separate paper.
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Shetty, Devdas, Claudio Campana, and Nikolay Nazaryan. "Modeling and Experimental Evaluation of Monocrystalline Piezoelectric Materials for Electromechanical Actuation." In ASME 2012 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/imece2012-88301.
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A great amount of research is being conducted to incorporate smart material actuators in aerospace applications such as (1) turbo fan engines (2) servo flap actuators for helicopter rotor control. For example, a piezoelectric stack actuator, coupled with mechanical or hydraulic amplification could provide the actuation required for the variable pitch fan system with a potentially higher level of reliability. In addition, piezoelectric actuation system could do so at a lower overall weight. However, there are limitations with existing piezoelectric stack actuators relative to power requirements in high load applications, resulting heat that is generated due to resistance and internal friction within the piezoelectric materials currently being utilized. Therefore, a new approach has been investigated to improve these characteristics in order for piezoelectric stacks to be a feasible solution for these types of large scale applications. A new configuration involving dielectric, conductor, piezoelectric material in a particular sequence of stack actuation is examined and experimented. This configuration is recommended due to the advantage that the metallic layers will allow creating the equipotential surfaces of the quartz and dielectric layers. This circumstance is very important because, in this case, it will take place instantly changing the electric potential of the surface of the piezoelectric material and the dielectric when the force or voltage applied to the actuator changes instantly. A nonlinear lumped parameter model of a piezoelectric stack has been developed to describe the behavior for the purpose of control actuation analysis.
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Kerkvliet, Maarten, Guilherme Vaz, Nicolas Carette, and Michiel Gunsing. "Analysis of U-Type Anti-Roll Tank Using URANS: Sensitivity and Validation." In ASME 2014 33rd International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2014. http://dx.doi.org/10.1115/omae2014-23483.
Full textAbstract:
The roll motion of ships operating in a seaway is often limiting operations. These limits could be due to, e.g. maximum acceleration, green water, capsize risk or just comfort. Therefore additional roll damping is desired to prevent uncontrolled roll motion. Different means are available to decrease the roll motion of a ship, amongst other these include bilge keels, active fin stabilizers (either for forward or zero speed) and U-shape or free surface anti-roll tanks (ART). The amplitude and phase of the roll opposing moment resulting from the water that moves inside the ART are a function of the geometry of the tank and especially its internal damping. Due to the complex and non-linear nature of this flow, the use of Computational Fluid Dynamics (CFD) was chosen to analyse the details of the flow inside the tank and its anti-roll performance. The present paper focuses on the sensitivity and validation of the anti-roll performances of passive U-type ART using CFD. For this, the incompressible Unsteady Reynolds Averaged Navier-Stokes (URANS) code ReFRESCO was used. The sensitivity on the results for the U-tank is analysed by varying the grid resolution and the numerical time step. The two-dimensional (2D) full-scale and Froude based model-scale ReFRESCO results are compared to 2D and 3D full-scale CFD results of Delaunay (2012) [1] and Thanyamanta and Molyneux (2012) [2] and validated with model-scale experimental results of Field and Martin (1975) [3] and MARIN experimental results by Gunsing et al. (2014) [4]. This paper shows the influence of the convective scheme for capturing the free-surface interface and provides recommendations for a time step and grid resolution to effectively calculate the roll damping of an ART.
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Shih, T. I.-P., C. S. Lee, and K. M. Bryden. "Effects of Averaging the Heat-Transfer Coefficient on the Predicted Material Temperature Distribution." In ASME Turbo Expo 2015: Turbine Technical Conference and Exposition. American Society of Mechanical Engineers, 2015. http://dx.doi.org/10.1115/gt2015-43552.
Full textAbstract:
The heat-transfer coefficient (HTC) in internal-coolant passages can vary appreciably about a heat-transfer enhancement feature such as a pin fin, a rib, and a concavity because of stagnation regions and wakes about the enhancement feature. However, the computed or measured HTC is often averaged spatially in the spanwise direction or over some region when used in the design of cooling strategies. Since the variation in the HTC could be a factor of eight or more about an enhancement feature, it is of interest to understand the effects of averaging the HTC on the predicted temperature distribution in the solid subjected to the heating and cooling. In this computational study, a flat plate of thickness H (1 mm) and length L = 20H is heated on one side by either a constant heat flux (68 W/cm2) or a constant HTC (1,167.2 W/m2-K) and a constant hot-gas temperature (1,482 °C). On the cooled side, the free stream or bulk temperature is kept constant (400 °C) and the average HTC (1,442.5 W/m2-K) is kept constant as well. This average HTC on the cooled side is the average of a higher HTC (hH) and a lower HTC (hL). Two types of changes from hH to hL are considered — abrupt (or step) and gradual. When the HTC changes abruptly, hH is imposed over LH, and hL is imposed over LL=L–LH. When the HTC changes gradually from hH to hL, hH is imposed from from x = 0 to LH/2, and hL is imposed from x = 3LH/2 to L with a smooth variation in the HTC to connect hH and hL. Results obtained show that when the averaged HTC is used, the maximum temperature in the plate is 900 °C on the heated side of the plate. However, if the variation in the HTC is accounted for, then the maximum temperature in the plate could be as high as 1.363 times the maximum temperature predicted by assuming an averaged HTC. Also, for the range of parameters studied, the difference in the maximum and minimum temperature in the plate can increase by a factor of 16, which strongly affects thermal stress.
Reports on the topic "Interval type-2 FNN"
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Ørvig, Kjersti. Velferdsteknologi: En studie av holdninger/oppfatninger om bruk av velferdsteknologi for unge mennesker med nedsatt funksjonsevne i eller på vei til egen bolig. University of Stavanger, October 2014. http://dx.doi.org/10.31265/usps.225.
Full textAbstract:
Dette er en rapport som bygger på en sosiologisk studie av pårørende og brukeres oppfatninger i tilknytning til en fremtidig innføring av velferdsteknologi i bolig for unge mennesker med nedsatt funksjonsevne. Hovedhensikten med studien er å dokumentere og diskutere muligheter og begrensninger ved velferdsteknologisk understøttelse i bolig slik den enkelte bruker/pårørende oppfatter dette. Målgruppen for studien er unge voksne (18-29 år) med nedsatt funksjonsevne som enten bor i egen bolig eller er på vei til egen bolig. Dette er en gruppe unge mennesker som har vært og fremdeles er lite synlig i debatten rundt innføring av velferdsteknologi som i all hovedsak har vært rettet mot eldre og/eller kronisk syke. Min analyse fokuseres rundt fem hovedtema: 1) kunnskaps- og kompetanseforutsetninger, 2) teknologiske utfordringer, 3) ny teknologi og det menneskelige aspektet, 4) fordeler og ulemper med moderne teknologi og 5) de blandede erfaringene med Nav. Et overordnet spørsmål i rapporten er hvordan velferdsteknologi kan bidra til inkludering for unge mennesker med funksjonsnedsettelser. Det ble anvendt en kvalitativ metode i studiet med bruk av semi-strukturerte intervjuer. Utvalget av informanter i målgruppen ble strategisk valgt i samsvar med prosjektets forskningsspørsmål. Dette omfattet unge voksne brukere (18-29 år) med nedsatt kognitiv og/eller fysisk funksjon samt pårørende til brukere i denne aldersgruppen. Et annet kriterium var at brukerne enten bodde i egen bolig eller var på vei til egen bolig de nærmeste årene. Totalt 13 informanter deltok, herav 5 brukere og 8 pårørende. 3 av de 5 brukerne som deltok i undersøkelsen bodde i egen bolig. Av det totale antallet brukere som var representert i undersøkelsen bodde 5 av brukere i egen bolig. Intervjuene ble gjennomført i fem kommuner i Rogaland høsten 2013 og vår 2014. Hvert intervju ble tatt opp på bånd og transkribert. Informantene ble rekruttert via to ulike interesseorganisasjoner. Funn Et hovedfunn viser at det er et stort behov for informasjon og kunnskap om hva velferdsteknologi omfatter og hva som er forskjellen på velferdsteknologi og mer tradisjonelle hjelpemidler. Samtidig indikerer funn at noen av brukerne og flere av de pårørende har kunnskap og kompetanse i bruk av smarttelefoner, pc, nettbrett etc. Dette er kunnskap som kan videreutvikles til bruk av ulike typer mer spesialtilpassede kommunikasjonsløsninger. Manglende tilgjengelig informasjon kan bidra til at det skapes ambivalente holdninger til ny teknologi. Dette er knyttet til oppfatninger om overvåkning og kontroll. En utfordring som kommer til uttrykk blant pårørende informantene i tilknytning til velferdsteknologi, er situasjoner hvor pårørende/bruker mangler digital kompetanse. Pårørende uttrykker i den sammenheng bekymring for ekskludering av en gruppe brukere som ikke får tilgang til moderne teknologi fordi det ikke søkes om dette. Resultatet kan bli at det ikke søkes om velferdsteknologiske løsninger fordi pårørende/sosiale nettverk ikke selv har kompetanse eller ikke bryr seg om å erverve denne kompetansen. Brukere som er avhengig av pårørende/sosiale nettverk for å håndtere teknologien kan bli særlig sårbare i denne sammenhengen. Et viktig funn som kommer frem her er at det må opprettes en type support gjennom Nav. Denne type support må være tilgjengelig i situasjoner hvor teknologien ikke fungerer som den skal eller ved andre behov for assistanse. Funn peker og på behovet for å sikre opplæring av kommunalt ansatte som mangler grunnleggende kompetanse om velferdsteknologi. Dette er i samsvar med flere fagrapporter på feltet. Et sentralt funn i undersøkelsen omfatter frykten for at velferdsteknologi skal erstatte menneskelig kontakt. Dette er i samsvar med «motstanderne» i debatten rundt innføring av moderne teknologi. Flere av informantene uttrykte og stor skepsis til ulike type overvåkningsutstyr av tjenestemottaker. Møtet med Nav/hjelpemidler viser at mange av mine informanter har svært blandede erfaringer i forhold til informasjon om moderne velferdsteknologiske løsninger (smarthusløsninger) samt få innvilget søknader til mer tradisjonelle hjelpemidler. Ingen av informantene har på noe tidspunkt fått tilbud om smarthusløsninger i bolig. Dette kan skyldes manglende kompetanse og kunnskap om velferdsteknologiske løsninger fra kommunens side samt representere en flaskehals i forhold til implementering av velferdsteknologi. En annen grunn kan være lav innkjøpskompetanse og svak økonomi. Bruk av ulike moderne teknologiske løsninger kan bidra til at mennesker med nedsatt funksjonsevne kan få en større grad av selvstendighet og kunne delta på flere av livets områder. En viktig forutsetning i denne sammenheng omfatter tilrettelegging og opplæring av funksjonshemmede, pårørende og sosiale nettverk samt aktører som har ansvar for tilrettelegging.