133,564 research outputs found
A novel three-phase UPS system with a single-phase resonant HF link
No full textThis paper presents a new three-phase uninterruptible power supply (UPS) system based on a single-phase resonant high frequency (HF) link and a single-phase transformer. The three-phase output voltage is constructed and regulated from a three-phase cycloconverter fed from the constant amplitude, constant frequency link voltage. The generation of a novel switching stategy for the three-phase cycloconverter is presented. The simulation of the proposed system is carried out and verified with experimental results
Development of a novel fully coupled solver in OpenFOAM: Steady-state incompressible turbulent flows
No full textIn this work a block coupled algorithm for the solution of three-dimensional incompressible turbulent flows is presented. A cell-centered finite-volume method for unstructured grids is employed. The interequation coupling of the incompressible Navier-Stokes equations is obtained using a SIMPLE-type algorithm with a Rhie-Chow interpolation technique. Due to the simultaneous solution of momentum and continuity equations, implicit block coupling of pressure and velocity variables leads to faster convergence compared to classical, loosely coupled, segregated algorithms of the SIMPLE family of algorithms. This gain in convergence speed is accompanied by an improvement in numerical robustness. Additionally, a two-equation eddy viscosity turbulence model is solved in a segregated fashion. The substnatially improved performance of the block coupled approach compared to the segregated approach is demonstrated in a set of test cases. It is shown that the scalability of the coupled solution algorithm with increasing numbers of cells is nearly linear. To achieve this scalability, an algebraic multigrid solver for block coupled systems of equations has been implemented and used as linear solver for the system of block equations. The presented algorithm has been entirely embedded into the leading open-source computational fluid dynamics (CFD) library OpenFOAM. © 2014 Taylor and Francis Group, LLC.Benzi M, 2005, ACT NUMERIC, V14, P1, DOI 10.1017-S0962492904000212; Brandt A., 1977, MATH COMPUT; Casartelli E., 2012, INT C EXH INN APPR G; DACLESMARIANI J, 1995, AIAA J, V33, P1561, DOI 10.2514-3.12826; Darwish M., 2001, NUMER HEAT TRANSFE B; Darwish M., 2000, INT J NUMER METH FLU; Darwish M., 2003, INT J HEAT MASS TRAN; Darwish M., 2008, J COMPUT PHYS; Darwish M., 2004, NUMER HEAT TRANSFE B; de Lemos MJS, 2000, NUMER HEAT TR B-FUND, V37, P489; Doormaal J. V., 1986, NAT HEAT TRANSF C DE; Doormaal J. V., 1984, NUMER HEAT TRANSFER; Federenko R., ZH VYCHISL MAT MAT F, P922; Ferziger J., 1994, COMPUTATIONAL METHOD; Hutchinson B., 1986, NUMER HEAT TRANSFER; Keller S., 2004, P 10 BRAZ C THERM SC; Laia Y. G., 1997, NUMER HEAT TRANSFE B, V32, P267; Menter F., 1994, AIAA J; Menter F. R., 2003, TURBULENCE HEAT MASS; Moukalled F., 2000, NUMER HEAT TRANSFE B; Muzaferija S., 1994, THESIS U LONDON LOND; Patankar S., 1972, INT J HEAT MASS TRAN; Patankar S. V., 1980, NUMERICAL HEAT TRANS; Poussin F., 1968, SIAM J NUMER ANAL; Rhie C., 1983, AIAA J; Singh D., 2013, NUMER HEAT TRANSFE A; Vradis C., 1998, NUMERICAL HEAT TRANS, V33, P79; Weller H., 1998, COMPUT PHYS; Woodfield PL, 2003, NUMER HEAT TR B-FUND, V43, P403, DOI 10.1080-104077903901221223
Political and Humanitarian Commitment in the Poetry of Mahmoud Darwish
No full textThe research represents an endeavor to analyze "the literature of the Palestinian poet Mahmoud Darwish" concerning the themes of political and humanitarian commitment in his poetry. It explores how the poet grappled with the tragedy of the Palestinian issue, wherein entire lives were transformed into a resistance and struggle for existence and identity against a usurping and deadly enemy that sought to subvert facts and camouflage matters. Through literature, Mahmoud Darwish sought to depict the plight of the Palestinian individual, the suffering endured, and the aspirations tied to the liberation of a land unjustly stolen. Darwish endeavored to articulate the dreams of refugees and displaced individuals, emphasizing the longing to return to their homeland, Palestine. For him, this return represented a dream that must be realized, as it serves as a guarantee for the survival of Palestine and the preservation of Palestinian self, existence, and identity. In pursuit of this objective, Mahmoud Darwish employed a variety of literary styles, employing the most apt words and structures with exceptional skill. His proficiency allowed him to resist occupation, thereby securing Palestine for its people and maintaining it as a haven of peace
Convective schemes for capturing interfaces of free-surface flows on unstructured grids
No full textIn this article, the general methodology used in constructing interface-capturing schemes is clarified and concisely described. Moreover, a new interface-capturing scheme, denoted STACS and based on a switching strategy, is developed. The accuracy of the new scheme is compared to the well-known CICSAM and HRIC schemes by solving four pure advection test problems. Results, displayed in the form of interface contours for the various schemes, reveal deterioration in the accuracy of the CICSAM and HRIC schemes, with their performance approaching that of the UPWIND scheme as the Courant number increases. On the other hand, predictions obtained with the new STACS scheme are by far more accurate and less diffusive, preserving interface sharpness and boundedness at all Courant number values considered.BRACKBILL JU, 1992, J COMPUT PHYS, V100, P335, DOI 10.1016-0021-9991(92)90240-Y; BRANDT A, 1977, MATH COMPUT, V31, P333; Cleary PW, 2000, INT J CAST METAL RES, V12, P357; Darwish M, 1996, COMPUT METHOD APPL M, V129, P221, DOI 10.1016-0045-7825(95)00881-0; Darwish M, 2001, NUMER HEAT TR B-FUND, V40, P99; Darwish M, 2000, NUMER HEAT TR B-FUND, V37, P227; DARWISH M, 2000, P 36 AIAA ASME SAE A; DARWISH M, 2002, P IASTED INT C APPL; Darwish MS, 1998, NUMER HEAT TR B-FUND, V34, P191, DOI 10.1080-10407799808915054; Darwish MS, 2003, INT J HEAT MASS TRAN, V46, P599, DOI 10.1016-S0017-9310(02)00330-7; DARWISH MS, 1993, NUMER HEAT TR B-FUND, V24, P353, DOI 10.1080-10407799308955898; Ha J., 1999, P 2 INT C CFD MIN PR; HARLOW FH, 1971, LA4700 LASA; Harvie DJE, 2001, INT J NUMER METH FL, V35, P151, DOI 10.1002-1097-0363(20010130)35:2151::AID-FLD873.0.CO;2-4; HIRT CW, 1981, J COMPUT PHYS, V39, P201, DOI 10.1016-0021-9991(81)90145-5; Jasak H, 1996, THESIS TECHNOLOGY ME; Kothe D B, 1999, P 3 ASME JSME JOINT; KOTHE DB, 1992, AIAA J, V30, P2694, DOI 10.2514-3.11286; LAFAURIE B, 1994, J COMPUT PHYS, V113, P134, DOI 10.1006-jcph.1994.1123; LEONARD BP, 1990, COMPUT METH APPL MEC, P59; LEONARD BP, 1991, COMPUT FLUIDS, V19, P141, DOI 10.1016-0045-7930(91)90011-6; LEONARD BP, 1990, INT J NUMER METH ENG, V30, P729, DOI 10.1002-nme.1620300412; LEONARD BP, 1991, COMPUT METHOD APPL M, V88, P17, DOI 10.1016-0045-7825(91)90232-U; Maronnier V, 1999, J COMPUT PHYS, V155, P439, DOI 10.1006-jcph.1999.6346; Darwish M, 2003, INT J NUMER METH FL, V41, P1221, DOI 10.1002-fld.490; MOUKALLED F, 1996, NUMER HEAT TRANSFE B, V31, P91; Moukalled F, 2001, J COMPUT PHYS, V168, P101, DOI 10.1006-jcph.2000.6683; Moukrim A, 2003, RAIRO-OPER RES, V37, P1, DOI 10.1051-ro:2003011; Muzaferija S, 1998, P 22 S NAV HYDR WASH, P638; Muzaferija S, 1998, NONLINEAR WATER WAVE, P59; Nichols B., 1980, LA8355; Nichols B.D., 1975, P 1 INT C NUM SHIP H; Noh W. F., 1976, LECTURE NOTES PHYSIC, V59, P330; OSHER S, 1983, J COMPUT PHYS, V50, P447, DOI 10.1016-0021-9991(83)90106-7; Puckett EG, 1991, P 4 INT S COMP FLUID, P933; RAMSHAW JD, 1976, J COMPUT PHYS, V21, P438, DOI 10.1016-0021-9991(76)90039-5; Renardy Y, 2002, J COMPUT PHYS, V183, P400, DOI 10.1006-jcph.2002.7190; Rhie C.M., 1986, 860207 AIAA; Rider WJ, 1998, J COMPUT PHYS, V141, P112, DOI 10.1006-jcph.1998.5906; RIDER WJ, 1995, P 12 AIAA CFD C SAN; Rudman M, 1997, INT J NUMER METH FL, V24, P671, DOI 10.1002-(SICI)1097-0363(19970415)24:7671::AID-FLD5083.0.CO;2-9; SHYY W, 1988, 883566CP AIAA; SHYY W, 1992, AIAA J, V30, P2660, DOI 10.2514-3.11282; Ubbink O, 1999, J COMPUT PHYS, V153, P26, DOI 10.1006-jcph.1999.6276; UNVERDI SO, 1992, J COMPUT PHYS, V100, P25, DOI 10.1016-0021-9991(92)90307-K; YOUNGS DL, 1984, 449235 AT WEAP RES E; ZALESAK ST, 1979, J COMPUT PHYS, V31, P335, DOI 10.1016-0021-9991(79)90051-223252
Expanding industrial thinking by formalizing the industrial engineering identity for the knowledge era
No full textTo date, the formal identity of the Industrial Engineer remains vague. D
ue to the broad knowledge base and
application areas made available to Industrial Engineers, pinning down the commonality has proven
difficult. This problem is further magnified by global forces shaping the knowledge era. Various works
touch on some elemen
ts that can help in forming an identity (such as IE skills, work preferences, thinking
styles...etc) but they have not been combined into a common identity. To do so is no easy task but for the
sake of the field it must be done. There is no doubt that IE kno
wledge is valuable and has proven itself, but
employers rarely hire a person with the title Industrial Engineer (rather it is process engineer, supply chain
manager...etc). Defining this brand and identity can massively improve awareness about the field itse
lf,
create a resource to refer students to and help develop new application areas for industrial thinking and
modernization of industrial methods
.
A modern understanding of the role of the Industrial Engineer can be
established (namely that they are the co
nnection to all fields of knowledge and a master of some) by
developing an Industrial Engineer
ing Identity and exemplifying the industrial thinking style
by means of
case studies on
facing or shaping
disruptive forces on the knowledge era
. The research pre
sentation shows
that the key requirements for the dissertation are the d
evelop
ment of
an
Industrial Engineering identity, the
definition of
the unique features of Industrial thinking
and the d
emonstrate the value gained by designing
artefacts with this new
identity in min
A fully coupled navier-stokes solver for fluid flow at all speeds
No full textThis article deals with the formulation and testing of a newly developed, fully coupled, pressure-based algorithm for the solution of fluid flow at all speeds. The new algorithm is an extension into compressible flows of a fully coupled algorithm developed by the authors for laminar incompressible flows. The implicit velocity-pressure-density coupling is resolved by deriving a pressure equation following a procedure similar to a segregated SIMPLE algorithm using the Rhie-Chow interpolation technique. The coefficients of the momentum and continuity equations are assembled into one matrix and solved simultaneously, with their convergence accelerated via an algebraic multigrid method. The performance of the coupled solver is assessed by solving a number of two-dimensional problems in the subsonic, transsonic, supersonic, and hypersonic regimes over several grid systems of increasing sizes. For a desired level of convergence, results for each problem are presented in the form of convergence history plots, tabulated values of the maximum number of required iterations, the total CPU time, and the CPU time per control volume. © 2014 Taylor and Francis Group, LLC.Abbasi R, 2013, COMPUT FLUIDS, V81, P68, DOI 10.1016-j.compfluid.2013.03.014; Acharya S, 2007, J HEAT TRANS-T ASME, V129, P407, DOI 10.1115-1.2716419; Anderson Jr J.D., 1982, MODERN COMPRESSIBLE; Anjorin V. A. O., 2001, INT J FLUID DYNAM, V5, P59; Barton IE, 1998, INT J NUMER METH FL, V26, P459, DOI 10.1002-(SICI)1097-0363(19980228)26:4459::AID-FLD6453.0.CO;2-U; BATINA JT, 1991, AIAA J, V29, P1836, DOI 10.2514-3.10808; Blokhin AM, 2009, SB MATH+, V200, P157, DOI 10.1070-SM2009v200n02ABEH003990; Cabboussat A., 2005, J COMPUT PHYS, V203, P626; Caretto L. S., 1972, Computer Methods in Applied Mechanics and Engineering, V1, DOI 10.1016-0045-7825(72)90020-5; Darwish M, 2001, NUMER HEAT TR B-FUND, V40, P99; Darwish M, 2007, NUMER HEAT TR B-FUND, V52, P353, DOI 10.1080-10407790701372785; Darwish M, 2004, NUMER HEAT TR B-FUND, V45, P49, DOI 10.1080-1040779049025487; Darwish M, 2009, J COMPUT PHYS, V228, P180, DOI 10.1016-j.jcp.2008.08.027; DEMIRDZIC I, 1993, INT J NUMER METH FL, V16, P1029, DOI 10.1002-fld.1650161202; Deng GB, 2001, COMPUT FLUIDS, V30, P445, DOI 10.1016-S0045-7930(00)00025-6; Dettmer W, 2006, COMPUT METHOD APPL M, V195, P3038, DOI 10.1016-j.cma.2004.07.057; Elling V, 2008, COMMUN PUR APPL MATH, V61, P1347, DOI 10.1002-cpa.20231; Favini B, 1996, INT J NUMER METH FL, V23, P589, DOI 10.1002-(SICI)1097-0363(19960930)23:6589::AID-FLD4443.3.CO;2-R; Grismer M. J., 1994, THESIS NOTRE DAME U; Hirsch C., 1990, NUMERICAL COMPUTATIO; HWANG CJ, 1993, AIAA J, V31, P61, DOI 10.2514-3.11319; Karlci K. C., 1986, THESIS U MINNESOTA; Khalid M. S., 2009, P WORLD C ENG 2009 W; Kissling K., 2010, 5 EUR C COMP FLUID D; Langtry RB, 2005, 2005522 AIAA; LIEN FS, 1993, J FLUID ENG-T ASME, V115, P717, DOI 10.1115-1.2910204; LIEN FS, 1994, COMPUT METHOD APPL M, V114, P123, DOI 10.1016-0045-7825(94)90165-1; MARCHI CH, 1994, NUMER HEAT TR B-FUND, V26, P293, DOI 10.1080-10407799408914931; Menter F, 2003, TURBULENCE HEAT MASS, V4, P2003; Modesto-Madera N. A., 2010, THESIS RENSSELAER PO; Moguen Y, 2013, J COMPUT APPL MATH, V246, P136, DOI 10.1016-j.cam.2012.10.029; Montero R. S., 2000, 200027 NASA ICASE; Moukalled F, 2003, J COMPUT PHYS, V190, P550, DOI 10.1016-S0021-9991(03)00297-3; Moukalled F, 2004, NUMER HEAT TR B-FUND, V45, P343, DOI 10.1080-10407790490268841; Darwish M, 2003, INT J NUMER METH FL, V41, P1221, DOI 10.1002-fld.490; Moukalled F, 2000, NUMER HEAT TR B-FUND, V37, P103; Moukalled F, 2002, NUMER HEAT TR B-FUND, V42, P259, DOI 10.1080-10407790190053941; Moukalled F, 2001, J COMPUT PHYS, V168, P101, DOI 10.1006-jcph.2000.6683; Muzaferija S, 1997, J COMPUT PHYS, V138, P766, DOI 10.1006-jcph.1997.5853; PATANKAR SV, 1972, INT J HEAT MASS TRAN, V15, P1787, DOI 10.1016-0017-9310(72)90054-3; Rhie C., 1983, AIAA J, V17, P1525; Rispoli F., 2009, ASME J APPL MECH, V76, DOI [10.1115-1.3062969, DOI 10.1115-1.3062969]; Rossow CC, 2007, J COMPUT PHYS, V220, P879, DOI 10.1016-j.jcp.2006.05.034; Shapiro A. H., 1953, DYNAMICS THERMODYNAM; Shapiro E, 2005, J COMPUT PHYS, V210, P584, DOI 10.1016-j.jcp.2005.05.001; Shterev KS, 2010, J COMPUT PHYS, V229, P461, DOI 10.1016-j.jcp.2009.09.042; Tao WQ, 2004, NUMER HEAT TR B-FUND, V45, P1, DOI 10.1080-1040779049025485; Tezduyar TE, 2006, COMPUT MECH, V38, P469, DOI 10.1007-s00466-005-0025-6; VANDOORMAAL JP, 1984, NUMER HEAT TRANSFER, V7, P147, DOI 10.1080-10407798408546946; van Wachem B. G. M., 2006, EUR C COMP FLUID DYN; van Wachem B. G. M., 2007, 6 INT C MULT FLOW IC; Yaldin Y., 1991, AIAA J, V29, P712; Yang JY, 2001, AIAA J, V39, P2082, DOI 10.2514-2.1231; ZHANG LX, 2011, J HYDRODYN, V23, P421
MeSH term explosion and author rank improve expert recommendations
No full textInformation overload is an often-cited phenomenon that reduces the productivity, efficiency and efficacy of scientists. One challenge for scientists is to find appropriate collaborators in their research. The literature describes various solutions to the problem of expertise location, but most current approaches do not appear to be very suitable for expert recommendations in biomedical research. In this study, we present the development and initial evaluation of a vector space model-based algorithm to calculate researcher similarity using four inputs: 1) MeSH terms of publications; 2) MeSH terms and author rank; 3) exploded MeSH terms; and 4) exploded MeSH terms and author rank. We developed and evaluated the algorithm using a data set of 17,525 authors and their 22,542 papers. On average, our algorithms correctly predicted 2.5 of the top 5/10 coauthors of individual scientists. Exploded MeSH and author rank outperformed all other algorithms in accuracy, followed closely by MeSH and author rank. Our results show that the accuracy of MeSH term-based matching can be enhanced with other metadata such as author rank
AL SHI’IR "WA’ADA FI KAFAN" LI MAHMUD DARWISH (DIRASAH TAHLILIYAH SIMIYAIYYAH LI FERDINAND DE SAUSSURE)
No full textPalestina merupakan negara yang memiliki catatan konflik terpanjang di
dunia, yakni sekitar 78 tahun menurut perhitungan sejarah umum. Konflik yang berkepanjangan tersebut memberikan pengaruh besar kepada penyair-penyair Palestina terhadap karya mereka, termasuk Mahmud Darwish. Mahmud Darwish adalah seorang penyair Palestina yang hidup antara 1941-2008, yang puisi-puisinya terpengaruh oleh konflik tersebut. Salah satu karya Mahmud Darwish adalah wa’ada fi kafan yang berisikan kisah temannya yang gugur di medan perang dan bagaimana anak-anak di palestina bertumbuh.
Penelitian ini berjudul as-Syi’ir Wa’A>da fi> Kafan li Mahmu>d Darwi>sy (Dira>sah Tahli>liyah Si>miya>iyyah li Ferdinand de Saussure). Penelitian ini menggunakan alat analisis berupa teori semiotika milik Ferdinand de Saussure untuk mengungkap makna yang terdapat pada puisi Wa’A>da fi> Kafan. Dalam teori ini terdapat istilah penanda (signifier) dan petanda (signified), penanda (signifier) adalah media bahasa sedangkan petanda (signified) adalah perwujudan makna dari penanda (signifier). Dalam penelitian ini bait-bait puisi berkedudukan sebagai signifier dan representasi dari puisi tersebut merupakan signified.
Hasil dari penelitian ini adalah perasaan takut dan khawatir yang dialami oleh Mahmud Darwish ketika kehilangan temannya dan keadaan anak-anak di Palestina yang dipaksa menjadi dewasa sebelum waktunya. Mereka tidak menangis dan bermain, tidak memiliki mimpi yang indah, dan mereka ikut merasakan dampak peperangan sejak kecil
Serum 25-hydroxyvitamin D predicts cognitive performance in adults
No full textHala Darwish,1 Pia Zeinoun,2 Husam Ghusn,3,4 Brigitte Khoury,2 Hani Tamim,5 Samia J Khoury6 1Hariri School of Nursing, Faculty of Medicine, American University of Beirut, Beirut, Lebanon; 2Psychiatry Department, Faculty of Medicine, American University of Beirut, Beirut, Lebanon; 3Internal Medicine Department, Faculty of Medicine, American University of Beirut, Beirut, Lebanon; 4Geriatrics Department, Ain Wazein Hospital, El Chouf, Lebanon; 5Clinical Research Institute, Faculty of Medicine, American University of Beirut, Beirut, Lebanon; 6Neurology Department, Faculty of Medicine, American University of Beirut, Beirut, Lebanon Background: Vitamin D is an endogenous hormone known to regulate calcium levels in the body and plays a role in cognitive performance. Studies have shown an association between vitamin D deficiency and cognitive impairment in older adults. Lebanon has a high 25-hydroxyvitamin D (25(OH)D) deficiency prevalence across all age groups. Methods: In this cross-sectional study, we explored the cognitive performance and serum 25(OH)D levels using an electrochemoluminescent immunoassay in 254 older (>60 years) as well as younger (30–60 years) adults. Subjects’ characteristics, including age, years of education, wearing of veil, alcohol consumption, smoking, and physical exercise, were collected. Participants were screened for depression prior to cognitive screening using the Montreal Cognitive Assessment Arabic version. Visuospatial memory was tested using the Rey Complex Figure Test and Recognition Trial, and speed of processing was assessed using the Symbol Digit Modalities test. Results: Pearson’s correlation and stepwise linear regression analyses showed that a low vitamin D level was associated with greater risk of cognitive impairment in older as well as younger adults. Conclusion: These findings suggest that correction of vitamin D needs to be explored as an intervention to prevent cognitive impairment. Prospective longitudinal studies are needed to ascertain the effect of such interventions. Keywords: cognitive function, aging, neuro-psychological functio
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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