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809 results on '"Chang, C.S."'

1. NSTX-U research advancing the physics of spherical tokamaks.

Author

Berkery, J.W., Adebayo-Ige, P.O., Al Khawaldeh, H., Avdeeva, G., Baek, S-G., Banerjee, S., Barada, K., Battaglia, D.J., Bell, R.E., Belli, E., Belova, E.V., Bertelli, N., Bisai, N., Bonoli, P.T., Boyer, M.D., Butt, J., Candy, J., Chang, C.S., Clauser, C.F., and Corona Rivera, L.D.

Subjects
TOKAMAKS, HARMONIC oscillators, PLASMA transport processes, PHYSICS research, HEAT flux, RESEARCH personnel
Abstract

The objectives of NSTX-U research are to reinforce the advantages of STs while addressing the challenges. To extend confinement physics of low- A, high beta plasmas to lower collisionality levels, understanding of the transport mechanisms that set confinement performance and pedestal profiles is being advanced through gyrokinetic simulations, reduced model development, and comparison to NSTX experiment, as well as improved simulation of RF heating. To develop stable non-inductive scenarios needed for steady-state operation, various performance-limiting modes of instability were studied, including MHD, tearing modes, and energetic particle instabilities. Predictive tools were developed, covering disruptions, runaway electrons, equilibrium reconstruction, and control tools. To develop power and particle handling techniques to optimize plasma exhaust in high performance scenarios, innovative lithium-based solutions are being developed to handle the very high heat flux levels that the increased heating power and compact geometry of NSTX-U will produce, and will be seen in future STs. Predictive capabilities accounting for plasma phenomena, like edge harmonic oscillations, ELMs, and blobs, are being tested and improved. In these ways, NSTX-U researchers are advancing the physics understanding of ST plasmas to maximize the benefit that will be gained from further NSTX-U experiments and to increase confidence in projections to future devices. [ABSTRACT FROM AUTHOR]

Published
2024
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4. Pulsed Wire Magnetic-Field Measurement System on Permanent Magnet Quadrupoles

Author

Chen, Chih Wei, Chang, C.S., Chen, Hsiung, Chu, Yun-Liang, Lin, Fu-Yuen, Yang, Chin-Kang, and Huang, Jui-Che

Abstract

The adjustable strength permanent magnet quadrupoles used in this study were designed and manufactured at the National Synchrotron Radiation Research Center (NSRRC). The permanent magnet quadrupole had a bore radius of 3.5 mm and an effective length of 50 mm. It was based on SmCo blocks and provided an effective gradient field from 325 T/m to 355 T/m. Typical methods for measuring the magnetic-field performance of quadrupole magnets are the stretched-wire and rotating coil measurement systems. A pulsed-wire measurement (PWM) system was used to measure the magnetic fields of an in-vacuum undulator at the NSRRC. The PWM system provides quick measurements of the magnetic fields and is easy to install on any permanent accelerator magnet. In this work, a PWM system was used to measure the magnetic-field integrals and the multipole errors of quadrupole magnets. Comparison was made of the magnetic field results obtained with PWM and stretched-wire measurement methods.

Published
2024
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5. Fusion Energy Sciences Network Requirements Review (Final Report)

Author

Wala, Fatema, primary, Bonoli, Paul, additional, Brown, Ben, additional, Chang, C.S., additional, Churchill, Michael, additional, Cook, Brandon, additional, Curry, Doug, additional, Dart, Eli, additional, Diallo, Ahmed, additional, Dorland, Bill, additional, Fiuza, Frederico, additional, Foster, Mark, additional, Gerber, Richard, additional, Green, David, additional, Guok, Chin, additional, Guttenfelder, Walter, additional, Hicks, Susan, additional, Hier-Majumder, Saswata, additional, Hughes, Jerry, additional, Kafader, James, additional, Kampel, Scott, additional, Kaye, Stan, additional, King, Josh, additional, Lau, Cornwell, additional, Mandrekas, John, additional, Meneghini, Orso, additional, Miller, Bill, additional, Miller, Ken, additional, Monga, Inder, additional, Nazikian, Raffi, additional, Nguyen, Jeff, additional, Poli, Francesca, additional, Rapp, Jurgen, additional, Riley, Katherine, additional, Rotman, Lauren, additional, Sabbagh, Steve, additional, Savage, Brandon, additional, Schissel, David, additional, Schumacher, Douglass, additional, Stephey, Laurie, additional, Stillerman, Josh, additional, Wiedlea, Andrew, additional, Youchison, Dennis, additional, and Zurawski, Jason, additional

Published
2022
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9. Rethinking First Language–Second Language Similarities and Differences in English Proficiency: Insights From the ENglish Reading Online (ENRO) Project

Author

Siegelman, N, Elgort, I, Brysbaert, M, Agrawal, N, Amenta, S, Arsenijević Mijalković, J, Chang, C.S., Chernova, D, Chetail, F, Clarke, A.J.B., Content, A, Crepaldi, D, Davaabold, N, Delgersuren, S, Deutsch, A, Dibrova, V, Drieghe, D, Filipović Đurđević, Dušica, Finch, B, Frost, R, Gattei, C.A., Geva, E, Godfroid, A, Griener, L, Hernández-Rivera, E, Ivanenko, A, Järvikivi, J, Kawaletz, L, Khare, A, Lee, J.R., Lee, C.E., Manouilidou, C, Marelli, M, Mashanlo, T, Mišić, Ksenija, Miwa, K, Palma, P, Plag, I, Rezanova, Z, Riimed, E, Rueckl, J, Schroeder, S, Sekerina, I.A., Shalom, D.E., Slioussar, N, Slosar, N.M., Taler, V, Thériault, K, Titone, D, Tumee, O, Wetering, R.V.D., Verma, A, Weiss, A.F., Wu, D.H., Kuperman, V., Siegelman, N, Elgort, I, Brysbaert, M, Agrawal, N, Amenta, S, Arsenijević Mijalković, J, Chang, C.S., Chernova, D, Chetail, F, Clarke, A.J.B., Content, A, Crepaldi, D, Davaabold, N, Delgersuren, S, Deutsch, A, Dibrova, V, Drieghe, D, Filipović Đurđević, Dušica, Finch, B, Frost, R, Gattei, C.A., Geva, E, Godfroid, A, Griener, L, Hernández-Rivera, E, Ivanenko, A, Järvikivi, J, Kawaletz, L, Khare, A, Lee, J.R., Lee, C.E., Manouilidou, C, Marelli, M, Mashanlo, T, Mišić, Ksenija, Miwa, K, Palma, P, Plag, I, Rezanova, Z, Riimed, E, Rueckl, J, Schroeder, S, Sekerina, I.A., Shalom, D.E., Slioussar, N, Slosar, N.M., Taler, V, Thériault, K, Titone, D, Tumee, O, Wetering, R.V.D., Verma, A, Weiss, A.F., Wu, D.H., and Kuperman, V.

Abstract

This article presents the ENglish Reading Online (ENRO) project that offers data on English reading and listening comprehension from 7,338 university-level advanced learners and native speakers of English representing 19 countries. The database also includes estimates of reading rate and seven component skills of English, including vocabulary, spelling, and grammar, as well as rich demographic and language background data. We first demonstrate high reliability for ENRO tests and their convergent validity with existing meta-analyses. We then provide a bird's-eye view of first (L1) and second (L2) language comparisons and examine the relative role of various predictors of reading and listening comprehension and reading speed. Across analyses, we found substantially more overlap than differences between L1 and L2 speakers, suggesting that English reading proficiency is best considered across a continuum of skill, ability, and experiences spanning L1 and L2 speakers alike. We end by providing pointers for how researchers can mine ENRO data for future studies.

Published
2023

20. Overview of JET results for optimising ITER operation

Author

Mailloux, J., primary, Abid, N., additional, Abraham, K., additional, Abreu, P., additional, Adabonyan, O., additional, Adrich, P., additional, Afanasev, V., additional, Afzal, M., additional, Ahlgren, T., additional, Aho-Mantila, L., additional, Aiba, N., additional, Airila, M., additional, Akhtar, M., additional, Albanese, R., additional, Alderson-Martin, M., additional, Alegre, D., additional, Aleiferis, S., additional, Aleksa, A., additional, Alekseev, A.G., additional, Alessi, E., additional, Aleynikov, P., additional, Algualcil, J., additional, Ali, M., additional, Allinson, M., additional, Alper, B., additional, Alves, E., additional, Ambrosino, G., additional, Ambrosino, R., additional, Amosov, V., additional, Sundén, E.Andersson, additional, Andrew, P., additional, Angelini, B.M., additional, Angioni, C., additional, Antoniou, I., additional, Appel, L.C., additional, Appelbee, C., additional, Aria, S., additional, Ariola, M., additional, Artaserse, G., additional, Arter, W., additional, Artigues, V., additional, Asakura, N., additional, Ash, A., additional, Ashikawa, N., additional, Aslanyan, V., additional, Astrain, M., additional, Asztalos, O., additional, Auld, D., additional, Auriemma, F., additional, Austin, Y., additional, Avotina, L., additional, Aymerich, E., additional, Baciero, A., additional, Bairaktaris, F., additional, Balbin, J., additional, Balbinot, L., additional, Balboa, I., additional, Balden, M., additional, Balshaw, C., additional, Balshaw, N., additional, Bandaru, V.K., additional, Banks, J., additional, Baranov, Yu.F., additional, Barcellona, C., additional, Barnard, A., additional, Barnard, M., additional, Barnsley, R., additional, Barth, A., additional, Baruzzo, M., additional, Barwell, S., additional, Bassan, M., additional, Batista, A., additional, Batistoni, P., additional, Baumane, L., additional, Bauvir, B., additional, Baylor, L., additional, Beaumont, P.S., additional, Beckett, D., additional, Begolli, A., additional, Beidler, M., additional, Bekris, N., additional, Beldishevski, M., additional, Belli, E., additional, Belli, F., additional, Belonohy, É., additional, Ben Yaala, M., additional, Benayas, J., additional, Bentley, J., additional, Bergsåker, H., additional, Bernardo, J., additional, Bernert, M., additional, Berry, M., additional, Bertalot, L., additional, Betar, H., additional, Beurskens, M., additional, Bickerton, S., additional, Bieg, B., additional, Bielecki, J., additional, Bierwage, A., additional, Biewer, T., additional, Bilato, R., additional, Bílková, P., additional, Birkenmeier, G., additional, Bishop, H., additional, Bizarro, J.P.S., additional, Blackburn, J., additional, Blanchard, P., additional, Blatchford, P., additional, Bobkov, V., additional, Boboc, A., additional, Bohm, P., additional, Bohm, T., additional, Bolshakova, I., additional, Bolzonella, T., additional, Bonanomi, N., additional, Bonfiglio, D., additional, Bonnin, X., additional, Bonofiglo, P., additional, Boocock, S., additional, Booth, A., additional, Booth, J., additional, Borba, D., additional, Borodin, D., additional, Borodkina, I., additional, Boulbe, C., additional, Bourdelle, C., additional, Bowden, M., additional, Boyd, K., additional, Mihalić, I.Božičević, additional, Bradnam, S.C., additional, Braic, V., additional, Brandt, L., additional, Bravanec, R., additional, Breizman, B., additional, Brett, A., additional, Brezinsek, S., additional, Brix, M., additional, Bromley, K., additional, Brown, B., additional, Brunetti, D., additional, Buckingham, R., additional, Buckley, M., additional, Budny, R., additional, Buermans, J., additional, Bufferand, H., additional, Buratti, P., additional, Burgess, A., additional, Buscarino, A., additional, Busse, A., additional, Butcher, D., additional, Cal, E.de la, additional, Calabrò, G., additional, Calacci, L., additional, Calado, R., additional, Camenen, Y., additional, Canal, G., additional, Cannas, B., additional, Cappelli, M., additional, Carcangiu, S., additional, Card, P., additional, Cardinali, A., additional, Carman, P., additional, Carnevale, D., additional, Carr, M., additional, Carralero, D., additional, Carraro, L., additional, Carvalho, I.S., additional, Carvalho, P., additional, Casiraghi, I., additional, Casson, F.J., additional, Castaldo, C., additional, Catalan, J.P., additional, Catarino, N., additional, Causa, F., additional, Cavedon, M., additional, Cecconello, M., additional, Challis, C.D., additional, Chamberlain, B., additional, Chang, C.S., additional, Chankin, A., additional, Chapman, B., additional, Chernyshova, M., additional, Chiariello, A., additional, Chmielewski, P., additional, Chomiczewska, A., additional, Chone, L., additional, Ciraolo, G., additional, Ciric, D., additional, Citrin, J., additional, Ciupinski, Ł., additional, Clark, M., additional, Clarkson, R., additional, Clements, C., additional, Cleverly, M., additional, Coad, J.P., additional, Coates, P., additional, Cobalt, A., additional, Coccorese, V., additional, Coelho, R., additional, Coenen, J.W., additional, Coffey, I.H., additional, Colangeli, A., additional, Colas, L., additional, Collins, C., additional, Collins, J., additional, Collins, S., additional, Conka, D., additional, Conroy, S., additional, Conway, B., additional, Conway, N.J., additional, Coombs, D., additional, Cooper, P., additional, Cooper, S., additional, Corradino, C., additional, Corrigan, G., additional, Coster, D., additional, Cox, P., additional, Craciunescu, T., additional, Cramp, S., additional, Crapper, C., additional, Craven, D., additional, Craven, R., additional, Esposito, M.Crialesi, additional, Croci, G., additional, Croft, D., additional, Croitoru, A., additional, Crombé, K., additional, Cronin, T., additional, Cruz, N., additional, Crystal, C., additional, Cseh, G., additional, Cufar, A., additional, Cullen, A., additional, Curuia, M., additional, Czarski, T., additional, Dabirikhah, H., additional, Molin, A.Dal, additional, Dale, E., additional, Dalgliesh, P., additional, Dalley, S., additional, Dankowski, J., additional, David, P., additional, Davies, A., additional, Davies, S., additional, Davis, G., additional, Dawson, K., additional, Dawson, S., additional, Day, I.E., additional, De Bock, M., additional, De Temmerman, G., additional, De Tommasi, G., additional, Deakin, K., additional, Deane, J., additional, Dejarnac, R., additional, Del Sarto, D., additional, Delabie, E., additional, Del-Castillo-Negrete, D., additional, Dempsey, A., additional, Dendy, R.O., additional, Devynck, P., additional, Di Siena, A., additional, Di Troia, C., additional, Dickson, T., additional, Dinca, P., additional, Dittmar, T., additional, Dobrashian, J., additional, Doerner, R.P., additional, Donné, A.J.H., additional, Dorling, S., additional, Dormido-Canto, S., additional, Douai, D., additional, Dowson, S., additional, Doyle, R., additional, Dreval, M., additional, Drewelow, P., additional, Drews, P., additional, Drummond, G., additional, Duckworth, Ph., additional, Dudding, H., additional, Dumont, R., additional, Dumortier, P., additional, Dunai, D., additional, Dunatov, T., additional, Dunne, M., additional, Ďuran, I., additional, Durodié, F., additional, Dux, R., additional, Dvornova, A., additional, Eastham, R., additional, Edwards, J., additional, Eich, Th., additional, Eichorn, A., additional, Eidietis, N., additional, Eksaeva, A., additional, El Haroun, H., additional, Ellwood, G., additional, Elsmore, C., additional, Embreus, O., additional, Emery, S., additional, Ericsson, G., additional, Eriksson, B., additional, Eriksson, F., additional, Eriksson, J., additional, Eriksson, L.G., additional, Ertmer, S., additional, Esquembri, S., additional, Esquisabel, A.L., additional, Estrada, T., additional, Evans, G., additional, Evans, S., additional, Fable, E., additional, Fagan, D., additional, Faitsch, M., additional, Falessi, M., additional, Fanni, A., additional, Farahani, A., additional, Farquhar, I., additional, Fasoli, A., additional, Faugeras, B., additional, Fazinić, S., additional, Felici, F., additional, Felton, R., additional, Fernandes, A., additional, Fernandes, H., additional, Ferrand, J., additional, Ferreira, D.R., additional, Ferreira, J., additional, Ferrò, G., additional, Fessey, J., additional, Ficker, O., additional, Field, A.R., additional, Figueiredo, A., additional, Figueiredo, J., additional, Fil, A., additional, Fil, N., additional, Finburg, P., additional, Fiorucci, D., additional, Fischer, U., additional, Fishpool, G., additional, Fittill, L., additional, Fitzgerald, M., additional, Flammini, D., additional, Flanagan, J., additional, Flinders, K., additional, Foley, S., additional, Fonnesu, N., additional, Fontana, M., additional, Fontdecaba, J.M., additional, Forbes, S., additional, Formisano, A., additional, Fornal, T., additional, Fortuna, L., additional, Fortuna-Zalesna, E., additional, Fortune, M., additional, Fowler, C., additional, Fransson, E., additional, Frassinetti, L., additional, Freisinger, M., additional, Fresa, R., additional, Fridström, R., additional, Frigione, D., additional, Fülöp, T., additional, Furseman, M., additional, Fusco, V., additional, Futatani, S., additional, Gadariya, D., additional, Gál, K., additional, Galassi, D., additional, Gałązka, K., additional, Galeani, S., additional, Gallart, D., additional, Galvão, R., additional, Gao, Y., additional, Garcia, J., additional, García-Muñoz, M., additional, Gardener, M., additional, Garzotti, L., additional, Gaspar, J., additional, Gatto, R., additional, Gaudio, P., additional, Gear, D., additional, Gebhart, T., additional, Gee, S., additional, Gelfusa, M., additional, George, R., additional, Gerasimov, S.N., additional, Gervasini, G., additional, Gethins, M., additional, Ghani, Z., additional, Gherendi, M., additional, Ghezzi, F., additional, Giacalone, J.C., additional, Giacomelli, L., additional, Giacometti, G., additional, Gibson, C., additional, Gibson, K.J., additional, Gil, L., additional, Gillgren, A., additional, Gin, D., additional, Giovannozzi, E., additional, Giroud, C., additional, Glen, R., additional, Glöggler, S., additional, Goff, J., additional, Gohil, P., additional, Goloborodko, V., additional, Gomes, R., additional, Gonçalves, B., additional, Goniche, M., additional, Goodyear, A., additional, Gore, S., additional, Gorini, G., additional, Görler, T., additional, Gotts, N., additional, Goulding, R., additional, Gow, E., additional, Graham, B., additional, Graves, J.P., additional, Greuner, H., additional, Grierson, B., additional, Griffiths, J., additional, Griph, S., additional, Grist, D., additional, Gromelski, W., additional, Groth, M., additional, Grove, R., additional, Gruca, M., additional, Guard, D., additional, Gupta, N., additional, Gurl, C., additional, Gusarov, A., additional, Hackett, L., additional, Hacquin, S., additional, Hager, R., additional, Hägg, L., additional, Hakola, A., additional, Halitovs, M., additional, Hall, S., additional, Hall, S.A., additional, Hallworth-Cook, S., additional, Ham, C.J., additional, Hamaguchi, D., additional, Hamed, M., additional, Hamlyn-Harris, C., additional, Hammond, K., additional, Harford, E., additional, Harrison, J.R., additional, Harting, D., additional, Hatano, Y., additional, Hatch, D.R., additional, Haupt, T., additional, Hawes, J., additional, Hawkes, N.C., additional, Hawkins, J., additional, Hayashi, T., additional, Hazael, S., additional, Hazel, S., additional, Heesterman, P., additional, Heidbrink, B., additional, Helou, W., additional, Hemming, O., additional, Henderson, S.S., additional, Henriques, R.B., additional, Hepple, D., additional, Herfindal, J., additional, Hermon, G., additional, Hill, J., additional, Hillesheim, J.C., additional, Hizanidis, K., additional, Hjalmarsson, A., additional, Ho, A., additional, Hobirk, J., additional, Hoenen, O., additional, Hogben, C., additional, Hollingsworth, A., additional, Hollis, S., additional, Hollmann, E., additional, Hölzl, M., additional, Homan, B., additional, Hook, M., additional, Hopley, D., additional, Horáček, J., additional, Horsley, D., additional, Horsten, N., additional, Horton, A., additional, Horton, L.D., additional, Horvath, L., additional, Hotchin, S., additional, Howell, R., additional, Hu, Z., additional, Huber, A., additional, Huber, V., additional, Huddleston, T., additional, Huijsmans, G.T.A., additional, Huynh, P., additional, Hynes, A., additional, Iliasova, M., additional, Imrie, D., additional, Imríšek, M., additional, Ingleby, J., additional, Innocente, P., additional, Insulander Björk, K., additional, Isernia, N., additional, Ivanova-Stanik, I., additional, Ivings, E., additional, Jablonski, S., additional, Jachmich, S., additional, Jackson, T., additional, Jacquet, P., additional, Järleblad, H., additional, Jaulmes, F., additional, Rodriguez, J.Jenaro, additional, Jepu, I., additional, Joffrin, E., additional, Johnson, R., additional, Johnson, T., additional, Johnston, J., additional, Jones, C., additional, Jones, G., additional, Jones, L., additional, Jones, N., additional, Jones, T., additional, Joyce, A., additional, Juarez, R., additional, Juvonen, M., additional, Kalniņa, P., additional, Kaltiaisenaho, T., additional, Kaniewski, J., additional, Kantor, A., additional, Kappatou, A., additional, Karhunen, J., additional, Karkinsky, D., additional, Kashchuk, Yu, additional, Kaufman, M., additional, Kaveney, G., additional, Kazakov, Ye.O., additional, Kazantzidis, V., additional, Keeling, D.L., additional, Kelly, R., additional, Kempenaars, M., additional, Kennedy, C., additional, Kennedy, D., additional, Kent, J., additional, Khan, K., additional, Khilkevich, E., additional, Kiefer, C., additional, Kilpeläinen, J., additional, Kim, C., additional, Kim, Hyun-Tae, additional, Kim, S.H., additional, King, D.B., additional, King, R., additional, Kinna, D., additional, Kiptily, V.G., additional, Kirjasuo, A., additional, Kirov, K.K., additional, Kirschner, A., additional, kiviniemi, T., additional, Kizane, G., additional, Klas, M., additional, Klepper, C., additional, Klix, A., additional, Kneale, G., additional, Knight, M., additional, Knight, P., additional, Knights, R., additional, Knipe, S., additional, Knolker, M., additional, Knott, S., additional, Kocan, M., additional, Köchl, F., additional, Kodeli, I., additional, Kolesnichenko, Y., additional, Kominis, Y., additional, Kong, M., additional, Korovin, V., additional, Kos, B., additional, Kos, D., additional, Koslowski, H.R., additional, Kotschenreuther, M., additional, Koubiti, M., additional, Kowalska-Strzęciwilk, E., additional, Koziol, K., additional, Krasilnikov, A., additional, Krasilnikov, V., additional, Kresina, M., additional, Krieger, K., additional, Krishnan, N., additional, Krivska, A., additional, Kruezi, U., additional, Książek, I., additional, Kukushkin, A.B., additional, Kumpulainen, H., additional, Kurki-Suonio, T., additional, Kurotaki, H., additional, Kwak, S., additional, Kwon, O.J., additional, Laguardia, L., additional, Lagzdina, E., additional, Lahtinen, A., additional, Laing, A., additional, Lam, N., additional, Lambertz, H.T., additional, Lane, B., additional, Lane, C., additional, Neto, E.Lascas, additional, Łaszyńska, E., additional, Lawson, K.D., additional, Lazaros, A., additional, Lazzaro, E., additional, Learoyd, G., additional, Lee, Chanyoung, additional, Lee, S.E., additional, Leerink, S., additional, Leeson, T., additional, Lefebvre, X., additional, Leggate, H.J., additional, Lehmann, J., additional, Lehnen, M., additional, Leichtle, D., additional, Leipold, F., additional, Lengar, I., additional, Lennholm, M., additional, Gutierrez, E. Leon, additional, Lepiavko, B., additional, Leppänen, J., additional, Lerche, E., additional, Lescinskis, A., additional, Lewis, J., additional, Leysen, W., additional, Li, L., additional, Li, Y., additional, Likonen, J., additional, Linsmeier, Ch., additional, Lipschultz, B., additional, Litaudon, X., additional, Litherland-Smith, E., additional, Liu, F., additional, Loarer, T., additional, Loarte, A., additional, Lobel, R., additional, Lomanowski, B., additional, Lomas, P.J., additional, López, J.M., additional, Lorenzini, R., additional, Loreti, S., additional, Losada, U., additional, Loschiavo, V.P., additional, Loughlin, M., additional, Louka, Z., additional, Lovell, J., additional, Lowe, T., additional, Lowry, C., additional, Lubbad, S., additional, Luce, T., additional, Lucock, R., additional, Lukin, A., additional, Luna, C., additional, Luna, E.de la, additional, Lungaroni, M., additional, Lungu, C.P., additional, Lunt, T., additional, Lutsenko, V., additional, Lyons, B., additional, Lyssoivan, A., additional, Machielsen, M., additional, Macusova, E., additional, Mäenpää, R., additional, Maggi, C.F., additional, Maggiora, R., additional, Magness, M., additional, Mahesan, S., additional, Maier, H., additional, Maingi, R., additional, Malinowski, K., additional, Manas, P., additional, Mantica, P., additional, Mantsinen, M.J., additional, Manyer, J., additional, Manzanares, A., additional, Maquet, Ph., additional, Marceca, G., additional, Marcenko, N., additional, Marchetto, C., additional, Marchuk, O., additional, Mariani, A., additional, Mariano, G., additional, Marin, M., additional, Marinelli, M., additional, Markovič, T., additional, Marocco, D., additional, Marot, L., additional, Marsden, S., additional, Marsh, J., additional, Marshall, R., additional, Martellucci, L., additional, Martin, A., additional, Martin, A.J., additional, Martone, R., additional, Maruyama, S., additional, Maslov, M., additional, Masuzaki, S., additional, Matejcik, S., additional, Mattei, M., additional, Matthews, G.F., additional, Matveev, D., additional, Matveeva, E., additional, Mauriya, A., additional, Maviglia, F., additional, Mayer, M., additional, Mayoral, M.-L., additional, Mazzi, S., additional, Mazzotta, C., additional, McAdams, R., additional, McCarthy, P.J., additional, McClements, K.G., additional, McClenaghan, J., additional, McCullen, P., additional, McDonald, D.C., additional, McGuckin, D., additional, McHugh, D., additional, McIntyre, G., additional, McKean, R., additional, McKehon, J., additional, McMillan, B., additional, McNamee, L., additional, McShee, A., additional, Meakins, A., additional, Medley, S., additional, Meekes, C.J., additional, Meghani, K., additional, Meigs, A.G., additional, Meisl, G., additional, Meitner, S., additional, Menmuir, S., additional, Mergia, K., additional, Merriman, S., additional, Mertens, Ph., additional, Meshchaninov, S., additional, Messiaen, A., additional, Michling, R., additional, Middleton, P., additional, Middleton-Gear, D., additional, Mietelski, J., additional, Milanesio, D., additional, Milani, E., additional, Militello, F., additional, Asp, A.Militello, additional, Milnes, J., additional, Milocco, A., additional, Miloshevsky, G., additional, Minghao, C., additional, Minucci, S., additional, Miron, I., additional, Miyamoto, M., additional, Mlynář, J., additional, Moiseenko, V., additional, Monaghan, P., additional, Monakhov, I., additional, Moody, T., additional, Moon, S., additional, Mooney, R., additional, Moradi, S., additional, Morales, J., additional, Morales, R.B., additional, Mordijck, S., additional, Moreira, L., additional, Morgan, L., additional, Moro, F., additional, Morris, J., additional, Morrison, K.-M., additional, Msero, L., additional, Moulton, D., additional, Mrowetz, T., additional, Mundy, T., additional, Muraglia, M., additional, Murari, A., additional, Muraro, A., additional, Muthusonai, N., additional, N’Konga, B., additional, Na, Yong-Su, additional, Nabais, F., additional, Naden, M., additional, Naish, J., additional, Naish, R., additional, Napoli, F., additional, Nardon, E., additional, Naulin, V., additional, Nave, M.F.F., additional, Nedzelskiy, I., additional, Nemtsev, G., additional, Nesenevich, V., additional, Nestoras, I., additional, Neu, R., additional, Neverov, V.S., additional, Ng, S., additional, Nicassio, M., additional, Nielsen, A.H., additional, Nina, D., additional, Nishijima, D., additional, Noble, C., additional, Nobs, C.R., additional, Nocente, M., additional, Nodwell, D., additional, Nordlund, K., additional, Nordman, H., additional, Normanton, R., additional, Noterdaeme, J.M., additional, Nowak, S., additional, Nunn, E., additional, Nyström, H., additional, Oberparleiter, M., additional, Obryk, B., additional, O'Callaghan, J., additional, Odupitan, T., additional, Oliver, H.J.C., additional, Olney, R., additional, O’Mullane, M., additional, Ongena, J., additional, Organ, E., additional, Orsitto, F., additional, Orszagh, J., additional, Osborne, T., additional, Otin, R., additional, Otsuka, T., additional, Owen, A., additional, Oya, Y., additional, Oyaizu, M., additional, Paccagnella, R., additional, Pace, N., additional, Packer, L.W., additional, Paige, S., additional, Pajuste, E., additional, Palade, D., additional, Pamela, S.J.P., additional, Panadero, N., additional, Panontin, E., additional, Papadopoulos, A., additional, Papp, G., additional, Papp, P., additional, Parail, V.V., additional, Pardanaud, C., additional, Parisi, J., additional, Diaz, F.Parra, additional, Parsloe, A., additional, Parsons, M., additional, Parsons, N., additional, Passeri, M., additional, Patel, A., additional, Pau, A., additional, Pautasso, G., additional, Pavlichenko, R., additional, Pavone, A., additional, Pawelec, E., additional, Soldan, C.Paz, additional, Peacock, A., additional, Pearce, M., additional, Peluso, E., additional, Penot, C., additional, Pepperell, K., additional, Pereira, R., additional, Pereira, T., additional, Cippo, E.Perelli, additional, Pereslavtsev, P., additional, Perez von Thun, C., additional, Pericoli, V., additional, Perry, D., additional, Peterka, M., additional, Petersson, P., additional, Petravich, G., additional, Petrella, N., additional, Peyman, M., additional, Pillon, M., additional, Pinches, S., additional, Pintsuk, G., additional, Pires de Sá, W., additional, Pires dos Reis, A., additional, Piron, C., additional, Pionr, L., additional, Pironti, A., additional, Pitts, R., additional, van de Plassche, K.L., additional, Platt, N., additional, Plyusnin, V., additional, Podesta, M., additional, Pokol, G., additional, Poli, F.M., additional, Pompilian, O.G., additional, Popovichev, S., additional, Poradziński, M., additional, Porfiri, M.T., additional, Porkolab, M., additional, Porosnicu, C., additional, Porton, M., additional, Poulipoulis, G., additional, Predebon, I., additional, Prestopino, G., additional, Price, C., additional, Price, D., additional, Price, M., additional, Primetzhofer, D., additional, Prior, P., additional, Provatas, G., additional, Pucella, G., additional, Puglia, P., additional, Purahoo, K., additional, Pusztai, I., additional, Putignano, O., additional, Pütterich, T., additional, Quercia, A., additional, Rachlew, E., additional, Radulescu, G., additional, Radulovic, V., additional, Rainford, M., additional, Raj, P., additional, Ralph, G., additional, Ramogida, G., additional, Rasmussen, D., additional, Rasmussen, J.J., additional, Rattá, G., additional, Ratynskaia, S., additional, Rebai, M., additional, Réfy, D., additional, Reichle, R., additional, Reinke, M., additional, Reiser, D., additional, Reux, C., additional, Reynolds, S., additional, Richiusa, M.L., additional, Richyal, S., additional, Rigamonti, D., additional, Rimini, F.G., additional, Risner, J., additional, Riva, M., additional, Rivero-Rodriguez, J., additional, Roach, C.M., additional, Robins, R., additional, Robinson, S., additional, Robson, D., additional, Rodionov, R., additional, Rodrigues, P., additional, Ramos, M.Rodriguez, additional, Rodriguez-Fernandez, P., additional, Romanelli, F., additional, Romanelli, M., additional, Romanelli, S., additional, Romazanov, J., additional, Rossi, R., additional, Rowe, S., additional, Rowlands, D., additional, Rubel, M., additional, Rubinacci, G., additional, Rubino, G., additional, Ruchko, L., additional, Ruiz, M., additional, Ruiz, J.Ruiz, additional, Ruset, C., additional, Rzadkiewicz, J., additional, Saarelma, S., additional, Safi, E., additional, Sahlberg, A., additional, Salewski, M., additional, Salmi, A., additional, Salmon, R., additional, Salzedas, F., additional, Sanders, I., additional, Sandiford, D., additional, Santos, B., additional, Santucci, A., additional, Särkimäki, K., additional, Sarwar, R., additional, Sarychev, I., additional, Sauter, O., additional, Sauwan, P., additional, Scapin, N., additional, Schluck, F., additional, Schmid, K., additional, Schmuck, S., additional, Schneider, M., additional, Schneider, P.A., additional, Schwörer, D., additional, Scott, G., additional, Scott, M., additional, Scraggs, D., additional, Scully, S., additional, Segato, M., additional, Seo, Jaemin, additional, Sergienko, G., additional, Sertoli, M., additional, Sharapov, S.E., additional, Shaw, A., additional, Sheikh, H., additional, Sheikh, U., additional, Shepherd, A., additional, Shevelev, A., additional, Shigin, P., additional, Shinohara, K., additional, Shiraiwa, S., additional, Shiraki, D., additional, Short, M., additional, Sias, G., additional, Silburn, S.A., additional, Silva, A., additional, Silva, C., additional, Silva, J., additional, Silvagni, D., additional, Simfukwe, D., additional, Simpson, J., additional, Sinclair, D., additional, Sipilä, S.K., additional, Sips, A.C.C., additional, Sirén, P., additional, Sirinelli, A., additional, Sjöstrand, H., additional, Skinner, N., additional, Slater, J., additional, Smith, N., additional, Smith, P., additional, Snell, J., additional, Snoep, G., additional, Snoj, L., additional, Snyder, P., additional, Soare, S., additional, Solano, E.R., additional, Solokha, V., additional, Somers, A., additional, Sommariva, C., additional, Soni, K., additional, Sorokovoy, E., additional, Sos, M., additional, Sousa, J., additional, Sozzi, C., additional, Spagnolo, S., additional, Spelzini, T., additional, Spineanu, F., additional, Spong, D., additional, Sprada, D., additional, Sridhar, S., additional, Srinivasan, C., additional, Stables, G., additional, Staebler, G., additional, Stamatelatos, I., additional, Stancar, Z., additional, Staniec, P., additional, Stankūnas, G., additional, Stead, M., additional, Stefanikova, E., additional, Stephen, A., additional, Stephens, J., additional, Stevenson, P., additional, Stojanov, M., additional, Strand, P., additional, Strauss, H.R., additional, Strikwerda, S., additional, Ström, P., additional, Stuart, C.I., additional, Studholme, W., additional, Subramani, M., additional, Suchkov, E., additional, Sumida, S., additional, Sun, H.J., additional, Susts, T.E., additional, Svensson, J., additional, Svoboda, J., additional, Sweeney, R., additional, Sytnykov, D., additional, Szabolics, T., additional, Szepesi, G., additional, Tabia, B., additional, Tadić, T., additional, Tál, B., additional, Tala, T., additional, Tallargio, A., additional, Tamain, P., additional, Tan, H., additional, Tanaka, K., additional, Tang, W., additional, Tardocchi, M., additional, Taylor, D., additional, Teimane, A.S., additional, Telesca, G., additional, Teplova, N., additional, Teplukhina, A., additional, Terentyev, D., additional, Terra, A., additional, Terranova, D., additional, Terranova, N., additional, Testa, D., additional, Tholerus, E., additional, Thomas, J., additional, Thoren, E., additional, Thorman, A., additional, Tierens, W., additional, Tinguely, R.A., additional, Tipton, A., additional, Todd, H., additional, Tokitani, M., additional, Tolias, P., additional, Tomeš, M., additional, Tookey, A., additional, Torikai, Y., additional, von Toussaint, U., additional, Tsavalas, P., additional, Tskhakaya, D., additional, Turner, I., additional, Turner, M., additional, Turner, M.M., additional, Turnyanskiy, M., additional, Tvalashvili, G., additional, Tyrrell, S., additional, Tyshchenko, M., additional, Uccello, A., additional, Udintsev, V., additional, Urbanczyk, G., additional, Vadgama, A., additional, Valcarcel, D., additional, Valisa, M., additional, Olivares, P.Vallejos, additional, Vallhagen, O., additional, Valovič, M., additional, Van Eester, D., additional, Varje, J., additional, Vartanian, S., additional, Vasilopoulou, T., additional, Vayakis, G., additional, Vecsei, M., additional, Vega, J., additional, Ventre, S., additional, Verdoolaege, G., additional, Verona, C., additional, Rinati, G.Verona, additional, Veshchev, E., additional, Vianello, N., additional, Viezzer, E., additional, Vignitchouk, L., additional, Vila, R., additional, Villari, R., additional, Villone, F., additional, Vincenzi, P., additional, Vinyar, I., additional, Viola, B., additional, Virtanen, A.J., additional, Vitins, A., additional, Vizvary, Z., additional, Vlad, G., additional, Vlad, M., additional, Vondráček, P., additional, Vries, P.de, additional, Wakeling, B., additional, Walkden, N.R., additional, Walker, M., additional, Walker, R., additional, Walsh, M., additional, Wang, E., additional, Wang, N., additional, Warder, S., additional, Warren, R., additional, Waterhouse, J., additional, Watts, C., additional, Wauters, T., additional, Weckmann, A., additional, Maxwell, H.Wedderburn, additional, Weiland, M., additional, Weisen, H., additional, Weiszflog, M., additional, Welch, P., additional, Wendler, N., additional, West, A., additional, Wheatley, M., additional, Wheeler, S., additional, Whitehead, A., additional, Whittaker, D., additional, Widdowson, A., additional, Wiesen, S., additional, Wilkinson, J., additional, Williams, J.C., additional, Willoughby, D., additional, Wilson, I., additional, Wilson, J., additional, Wilson, T., additional, Wischmeier, M., additional, Wise, P., additional, Withenshaw, G., additional, Withycombe, A., additional, Witts, D., additional, Wojcik-Gargula, A., additional, Wolfrum, E., additional, Wood, R., additional, Woodley, C., additional, Woodley, R., additional, Woods, B., additional, Wright, J., additional, Wright, J.C., additional, Xu, T., additional, Yadikin, D., additional, Yajima, M., additional, Yakovenko, Y., additional, Yang, Y., additional, Yanling, W., additional, Yanovskiy, V., additional, Young, I., additional, Young, R., additional, Zabolockis, R.J., additional, Zacks, J., additional, Zagorski, R., additional, Zaitsev, F.S., additional, Zakharov, L., additional, Zarins, A., additional, Fernandez, D. Zarzoso, additional, Zastrow, K.-D., additional, Zayachuk, Y., additional, Zerbini, M., additional, Zhang, W., additional, Zhou, Y., additional, Zlobinski, M., additional, Zocco, A., additional, Zohar, A., additional, Zoita, V., additional, Zoletnik, S., additional, Zotta, V.K., additional, Zoulias, I., additional, Zwingmann, W., additional, and Zychor, I., additional

Published
2022
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21. NSTX-U theory, modeling and analysis results

Author

Guttenfelder, W., primary, Battaglia, D.J., additional, Belova, E., additional, Bertelli, N., additional, Boyer, M.D., additional, Chang, C.S., additional, Diallo, A., additional, Duarte, V.N., additional, Ebrahimi, F., additional, Emdee, E.D., additional, Ferraro, N., additional, Fredrickson, E., additional, Gorelenkov, N.N., additional, Heidbrink, W., additional, Ilhan, Z., additional, Kaye, S.M., additional, Kim, E.-H., additional, Kleiner, A., additional, Laggner, F., additional, Lampert, M., additional, Lestz, J.B., additional, Liu, C., additional, Liu, D., additional, Looby, T., additional, Mandell, N., additional, Maingi, R., additional, Myra, J.R., additional, Munaretto, S., additional, Podestà, M., additional, Rafiq, T., additional, Raman, R., additional, Reinke, M., additional, Ren, Y., additional, Ruiz, J. Ruiz, additional, Scotti, F., additional, Shiraiwa, S., additional, Soukhanovskii, V., additional, Vail, P., additional, Wang, Z.R., additional, Wehner, W., additional, White, A.E., additional, White, R.B., additional, Woods, B.J.Q., additional, Yang, J., additional, Zweben, S.J., additional, Banerjee, S., additional, Barchfeld, R., additional, Bell, R.E., additional, Berkery, J.W., additional, Bhattacharjee, A., additional, Bierwage, A., additional, Canal, G.P., additional, Chen, X., additional, Clauser, C., additional, Crocker, N., additional, Domier, C., additional, Evans, T., additional, Francisquez, M., additional, Gan, K., additional, Gerhardt, S., additional, Goldston, R.J., additional, Gray, T., additional, Hakim, A., additional, Hammett, G., additional, Jardin, S., additional, Kaita, R., additional, Koel, B., additional, Kolemen, E., additional, Ku, S.-H., additional, Kubota, S., additional, LeBlanc, B.P., additional, Levinton, F., additional, Lore, J.D., additional, Luhmann, N., additional, Lunsford, R., additional, Maqueda, R., additional, Menard, J.E., additional, Nichols, J.H., additional, Ono, M., additional, Park, J.-K., additional, Poli, F., additional, Rhodes, T., additional, Riquezes, J., additional, Russell, D., additional, Sabbagh, S.A., additional, Schuster, E., additional, Smith, D.R., additional, Stotler, D., additional, Stratton, B., additional, Tritz, K., additional, Wang, W., additional, and Wirth, B., additional

Published
2022
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29. Elastoplastic model for clay with microstructural consideration

Author

Chang, C.S., Hicher, P.-Y., Yin, Z.Y., and Kong, L.R.

Subjects
Mechanics -- Research, Anisotropy -- Observations, Clay -- Mechanical properties, Clay -- Models, Science and technology
Abstract

Clay material can be considered as a collection of clusters, which interact with each other mainly through mechanical forces. From this point of view, clay is modeled by analogy to granular material in this paper. An elastoplastic stress-strain relationship for clay is derived by using the granular mechanics approach developed in previous studies for sand. However, unlike sand, clay deformation is generated not only by the mobilizing but also by compressing clusters. Thus, in addition to the Mohr-Coulomb's plastic shear sliding and a dilatancy type flow role, a plastic normal deformation has been modeled for two clusters in compression. The overall stress-strain relationship can then be obtained from the mobilization and compressing of clusters through a static hypothesis of the macro-micro relations. The predictions are compared with the experimental results for clay under both drained and undrained triaxial loading conditions. Three different types of clay, including remolded and natural clay, have been selected to evaluate the model's performance. The comparisons verify that this model is capable of accurately reproducing the overall behavior of clay, which accounts for the influence of key parameters such as void ratio and mean stress. A section of this paper is devoted to show the model's capability of considering the influence of inherent anisotropy on the stress-strain response under undrained triaxial loading conditions. DOI: 10.1061/(ASCE)EM.1943-7889.0000013 CE Database subject headings: Clays; Microstructures; Stress strain relations; Anisotropy; Elastoplasticity.

Published
2009

30. Design of staggered undulators with dual magnet periods

Author

Cheng-Hsiang Chang, Ching-Shiang Hwang, Jyh-Chyuan Jan, Chang, C.S., and Chien-Te Chen

Subjects
Magnetic fields -- Analysis, Solenoids -- Evaluation, Superconducting magnets -- Design and construction, Synchrotron radiation sources -- Design and construction, Business, Electronics, Electronics and electrical industries
Published
2009

31. Model for granular materials with surface energy forces

Author

Chang, C.S. and Hicher, P.-Y.

Subjects
Lunar soil -- Mechanical properties, Granular materials -- Mechanical properties, Anisotropy -- Measurement, Soil structure -- Evaluation, Aerospace engineering -- Research, Aerospace and defense industries, Engineering and manufacturing industries, Science and technology
Abstract

In light of environmental differences (such as gravitational fields, surface temperatures, atmospheric pressures, etc.), the mechanical behavior of the subsurface soil on the Moon is expected to be different from that on the Earth. Before any construction on the Moon can be envisaged, a proper understanding of soil properties and its mechanical behavior in these different environmental conditions is essential. This paper investigates the possible effect of surface-energy forces on the shear strength of lunar soil. All materials, with or without a net surface charge, exhibit surface-energy forces, which act at a very short range. Although, these forces are negligible for usual sand or silty sand on Earth, they may be important for surface activated particles under extremely low lunar atmospheric pressure. This paper describes a constitutive modeling method for granular material considering particle level interactions. Comparisons of numerical simulations and experimental results on Hostun sand show that the model can accurately reproduce the overall mechanical behavior of soils under terrestrial conditions. The model is then extended to include surface-energy forces between particles in order to describe the possible behavior of lunar soil under extremely low atmospheric pressure conditions. Under these conditions, the model shows that soil has an increase of shear strength due to the effect of surface-energy forces. The magnitude of increased shear strength is in reasonable agreement with the observations of lunar soil made on the Moon's surface. DOI: 10.1061/(ASCE)0893-1321(2009)22:1(43) CE Database subject headings: Granular material; Stress-strain relations; Anisotropy; Elastoplasticity; Moon.

Published
2009

32. Multiobjective evolutionary optimization of substation maintenance using decision-varying Markov model

Author

Yang, F., Kwan, Chung Min, and Chang, C.S.

Subjects
Markov processes -- Evaluation, Algorithms -- Usage, Decision-making -- Methods, Electric substations -- Design and construction, Electric substations -- Management, Algorithm, Company business management, Business, Electronics, Electronics and electrical industries
Abstract

Reducing overall substation cost and improving reliability are the two prime but often conflicting objectives of electric power distribution. Proper scheduling of substation preventive maintenance provides an effective means to tradeoff between these two objectives. Decision-varying Markov models relating the deterioration process with maintenance operations is proposed to predict the availability of individual component. Minimum cut-sets method is employed to identify the critical components and evaluate the overall reliability of substation. A multiobjective evolutionary algorithm is proposed to optimize the two objectives to provide Pareto-fronts or tradeoff curves for a holistic view of the conflicting relationships between them. Through simulations, abilities of our proposed algorithm are demonstrated for robust search towards optimal solutions for large-size distribution. Index Terms--Decision-varying Markov model, minimum cut sets, multiobjective evolutionary algorithm, pareto front, substation maintenance.

Published
2008

33. Design and performance of a new magnetized magnet block on EPU structure

Author

Hwang, C.S., Chang, C.S., Lin, F.Y., Huang, M.H., Lin, P.H., Chang, C.H., and Chen, H.H.

Subjects
Synchrotron radiation sources -- Design and construction, Superconducting magnets -- Evaluation, Magnetic fields -- Analysis, Magnetization -- Analysis, Business, Electronics, Electronics and electrical industries
Abstract

A prototype of an Apple-II elliptically polarized undulator of length 0.46 m is constructed in order to test the performance of the newly designed magnet block, which is magnetized at a tilt angle 10 [degree]. The analysis has shown that the individual holder should be strong enough to prevent displacement of a magnet block when the phase shifts.

Published
2008

34. Elastic model for partially saturated granular materials

Author

Hicher, P.-Y. and Chang, C.S.

Subjects
Granular materials -- Mechanical properties, Stress-strain curves -- Evaluation, Elasticity -- Measurement, Soil mechanics -- Research, Science and technology
Abstract

This paper presents the development of an elastic model for partially saturated granular materials based on micromechanical factor consideration. A granular material is considered as an assembly of panicles. The stress-strain relationship for an assembly can be determined by integrating the behavior at all interpanicle contacts and by using a static hypothesis, which relates the average stress of the granular assembly to a mean field of particle contact forces. As for the nonsaturated state, capillary forces at grain contacts are added to the contact forces created by an external load. These are then calculated as a function of the degree of saturation, depending on the grain size distribution and on the void ratio of the granular assembly. Hypothesizing a Hertz-Mindlin law for the grain contacts leads to an elastic nonlinear behavior of the particulate material. The prediction of the stress-strain model is compared to experimental results obtained from several different granular materials in dry, partially saturated and fully saturated states. The numerical predictions demonstrate that the model is capable of taking into account the influence of key parameters, such as degree of saturation, void ratio, and mean stress. DOI: 10.1061/(ASCE)0733-9399(2008)134:6(505) CE Database subject headings: Granular materials; Stress strain relations; Elastic deformation; Unsaturated soils; Soil suction; Micromechanics.

Published
2008

37. Online source recognition of partial discharge for gas insulated substations using independent component analysis

Author

Chang, C.S., Jin, J., Chang, C., Hoshino, T., Hanai, M., and Kobayashi, N.

Subjects
Business, Electronics, Electronics and electrical industries
Abstract

To perform reliable insulation diagnosis for gas-insulated substation (GIS), detectable partial discharge (PD) should be identified quickly and effectively. With the increasing application of high voltage dc transmission, PD identification in such systems becomes more and more important. Therefore, a novel technique based on the analysis of ultra high frequency (UHF) resonance waveforms is proposed in this paper to meet the requirement. With the help of independent component analysis, the most dominating features are identified directly from UHF resonance signals without phase information. Using the identified features as the input, a neural network is implemented for recognizing sources of PD in S[F.sub.6] and separating from the corona in air within a very short time. Index Terms--Gas insulated substations, condition monitoring and insulation diagnosis, independent component analysis, online source recognition of partial discharge and corona.

Published
2006

38. Anisotropic nonlinear elastic model for particulate materials

Author

Hicher, P.-Y. and Chang, C.S.

Subjects
Anisotropy -- Analysis, Elasticity -- Analysis, Particles -- Properties, Earth sciences, Engineering and manufacturing industries, Science and technology
Abstract

This paper presents the development of an elastic model for particulate materials based on micromechanics considerations. A particulate material is considered as an assembly of particles. The stress-strain relationship for an assembly can be determined by integrating the behavior of the interparticle contacts in all orientations and using a static hypothesis which relates the average stress of the granular assembly to a mean field of particle contact forces. Hypothesizing a Hertz-Mindlin law for the particle contacts leads to an elastic nonlinear behavior of the particulate material, we were able to determine the elastic constants of the granular assembly based on the properties of the particle contacts. The numerical predictions, compared to the results obtained during experimental studies on different granular materials, show that the model is capable of taking into account both the influence of the inherent anisotropy and the influence of the stress-induced anisotropy for different stress conditions. DOI: 10.1061/(ASCE) 1090-0241 (2006) 132:8(1052) CE Database subject headings: Stress strain relations; Elasticity; Anisotropy; Micromechanics.

Published
2006

39. Evaluation of two homogenization techniques for modeling the elastic behavior of granular materials

Author

Hicher, P.-Y. and Chang, C.S.

Subjects
Anisotropy -- Analysis, Granular materials -- Usage, Micromechanics -- Analysis, Stress analysis (Engineering) -- Methods, Science and technology
Abstract

This paper discusses the capabilities of two homogenization techniques to accurately represent the elastic behavior of granular materials considered as assemblies of randomly distributed particles. The stress-strain relationship for the assembly is determined by integrating the behavior of the interparticle contacts in all orientations, using two different homogenization methods, namely the kinematic method and the static method. The numerical predictions obtained by these two homogenization techniques are compared to results obtained during experimental studies on different granular materials. Relations between elastic constants of the assembly, interparticle properties, and fabric parameters are discussed, as well as the capabilities of the models to take into account inherent and stress-induced anisotropy for different stress conditions. CE Database subject headings: Granular materials; Stress strain relations; Anisotropy; Constitutive models; Elasticity; Micromechanics; Homogeneity.

Published
2005

40. Source classification of partial discharge for gas insulated substation using waveshape pattern recognition

Author

Chang, C., Chang, C.S., Jin, J., Hoshino, T., Hanai, M., and Kobayashi, N.

Subjects
Wavelet transforms -- Research, Fourier transformations -- Research, Business, Electronics, Electronics and electrical industries
Abstract

Frequency-domain analysis of ultra-high frequency (UHF) signals for source identification of partial discharge (PD) occurring in S[F.sub.6] inside gas-insulated substation (GIS) has been widely covered in literature. In this, Fast Fourier Transform and Discrete Wavelet Transform based techniques have been extensively applied to derive classifying features from transformed patterns. On the other hand, it appears feasible to develop a time-domain classifier, which derives features directly from the original waveshape. The time-domain classifier is conceptually simple, and requires potentially less computing resources and simpler algorithmic interface with other intelligent techniques due to elimination of frequency-domain transformation. A novel classifier to extract features directly from time-domain waveforms is proposed for classifying S[F.sub.6] PD from air corona and among the three types of S[F.sub.6] PD, regardless of changes in PD locations and measurement conditions. Three sets of classifying features are proposed. Encouraging results have been achieved with comprehensive experimental data, which verifies and proves the usefulness and feasibility of the time-domain classifier. Index Terms--Waveshape analysis, time-domain classifier, pattern recognition, GIS.

Published
2005

41. Mix-mode elastic finite element formulation for bonded granular material considering rotation of particles

Author

Chang, C.S. and Shi, Q.

Subjects
Finite element method -- Research, Strains and stresses -- Research, Granular materials -- Research, Mechanics -- Research, Science and technology
Abstract

Rotation of particles in granular material is an important mechanism, which is responsible for the distinct feature of moment transfer within granular material. A couple-stress continuum is adopted to model such effect. The paper presents a mix-mode finite element formulation for the analysis of a couple stress continuum. A modified variational formulation is proposed to render unconditional convergence. The developed finite element method is validated by comparing the computed results with closed-form solutions. In order to verify whether the couple-stress continuum is appropriate for modeling granular media, finite element results for two different boundary value problems are performed and compared with that obtained from discrete analysis. Physical meaning of internal length, a new parameter of the material, is discussed. The suitability of the couple-stress continuum for modeling granular medium is evaluated. CE Database subject headings: Granular materials; finite element method; Bonding; Elastic analysis; Deformation analysis; Stress distribution; Numerical models; Two-dimensional analysis.

Published
2005

42. Analysis of UHF signal using prediction model

Author

Chang, C., Chang, C.S., Jin, J., Hoshino, Toshihiro, Hanai, Masahiro, and Kobayashi, Nobumitsu

Subjects
Business, Computers, Electronics, Electronics and electrical industries
Abstract

With increasing interest in the reduction of cost for operation and maintenance of S[F.sub.6] gas-insulated switchgear (GIS), various methods of condition monitoring have been developed and used in conjunction with highly sensitive sensors and advanced digital signal processing techniques. Detection of partial-discharge signals in GIS using ultra-high frequency (UHF) technique has gained wide acceptance in research and industry. Unlike approaches of fast Fourier transformation and discrete wavelet transformation (DWT), a novel method of using an adaptive linear combiner as a prediction model to analyze UHF signals is introduced in this paper. Successful results are obtained by applying this new method on field data measured by a UHF coupler. The feasibility of this new approach is studied and proved by the statistical distributions of the trained weights. Index Terms--Gas-insulated switchgear (GIS), partial-discharge (PD) waveshape analysis, prediction model.

Published
2004

43. Distributed mitigation of voltage sag by optimal placement of series compensation devices based on stochastic assessment

Author

Chang, C.S. and Yu, Zhemin

Subjects
Electric power systems -- Research, Business, Electronics, Electronics and electrical industries
Abstract

Central mitigation does not necessarily provide the most economical solution to voltage-sag problems. Distributed mitigation with strategically placed compensation devices should provide a better alternative. Placement studies of this nature usually involve extensive evaluations of candidate compensation schemes, which can become unmanageable for large systems with stochastic voltage-sag data. A probability-based technique known as the weighted sampling method is proposed to simplify the problem. The technique is applied to a distribution system to optimize the cost of placing series compensation. The cost has two components: device cost and cost reduction to consumers due to implementation of the device(s). Series compensation devices being optimized are the two distinctly different dynamic voltage restorer and thyristor voltage regulator. These devices are placed and optimized to best complement each other. To achieve reliable and fast convergence, a genetic algorithm with innovative coding is proposed. A 34-node distribution system is studied with a wide range of voltage-sag data and consumer tolerance characteristics. Index Terms--Dynamic voltage restorers, genetic algorithm, stochastic evaluation, thyristor voltage regulators, voltage sag mitigation for distribution system.

Published
2004

44. High brightness InGaN green LEDs with an ITO on n[superscript ++]-SPS upper contact

Author

Chang, C.S., Chang, S.J., Su, Y.K., Kuo, C.H., Lai, W.C., Lin, Y.C., Hsu, Y.P., Shei, S.C., Tsai, J.M., Lo, H.M., Ke, J.C., and Sheu, J.K.

Subjects
Optoelectronic devices -- Research, Light-emitting diodes -- Research, Optoelectronic device, Business, Electronics, Electronics and electrical industries
Abstract

Fabrication of nitride-based green light-emitting diodes is described and discussed.

Published
2003

45. Heterogeneous strain and bonded granular structure change in triaxial specimen studied by computer tomography

Author

Chang, C.S., Matsushima, T., and Lee, X.

Subjects
Strains and stresses -- Testing, Granular materials -- Testing, Science and technology
Abstract

In recent years, the method of x-ray computer tomography imaging has been used to characterize the microstructure of asphalt concrete, cement concrete, soil, and rock. This paper focuses on developing an algorithm that links the particle identity at different load steps and thus provides sequential movements of particles. The measured data from a specimen under triaxial load is analyzed to study the nonuniform strain field and to identify shear band formation. Packing structure change and the evolution of fabric tensors due to external load are discussed. The validity of a commonly used kinematic hypothesis in granular mechanics is also evaluated. CE Database subject headings: Radiography; Granular materials; Strain; Kinematics; Bonding.

Published
2003

46. Highly reliable nitride-based LEDs with SPS+ITO upper contacts

Author

Chang, S.J., Chang, C.S., Su, Y.K., Chuang, R.W., Lin, Y.C., Shei, S.C., Lo, H.M., Lin, H.Y., and Ke, J.C.

Subjects
Optoelectronic devices -- Research, Light-emitting diodes -- Research, Optoelectronic device, Business, Computers, Electronics, Electronics and electrical industries
Abstract

Research is described involving fabrication of nitride-based blue light emitting diodes (LED).

Published
2003

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