Relevant bibliographies by topics / NASA 42

Contents

  1. Journal articles
  2. Dissertations / Theses
  3. Books
  4. Book chapters
  5. Conference papers

Academic literature on the topic 'NASA 42'

Author: Grafiati
Published: 27 June 2021
Last updated: 18 February 2022

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles

Select a source type:

Consult the lists of relevant articles, books, theses, conference reports, and other scholarly sources on the topic 'NASA 42.'

Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.

You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.

Journal articles on the topic "NASA 42"

1

Bahtiar, Bahtiar, Muhammad Azrai, M. Arsyad Biba, and Muhammad Syakir. "Daya Saing Calon Varietas Hibrida Nasa 29 di Jawa Timur." Jurnal Penelitian Pertanian Tanaman Pangan 2, no. 1 (May 16, 2018): 35. http://dx.doi.org/10.21082/jpptp.v2n1.2018.p35-42.

Full text
APA, Harvard, Vancouver, ISO, and other styles
2

Grasha, Anthony F., and Kraig Schell. "Psychosocial Factors, Workload, and Human Error in a Simulated Pharmacy Dispensing Task." Perceptual and Motor Skills 92, no. 1 (February 2001): 53–71. http://dx.doi.org/10.2466/pms.2001.92.1.53.

Full text
Abstract:
Participants filled 42 orders on a task designed to simulate components of filling prescriptions. Task factors included objective workload of 70- versus 80-min. to complete the task and perceptions of workload dimensions using the NASA Task Load Index. The proportion and pattern of data-entry, counting, and product-selection errors were compatible with those found in pharmacy field-sites. Significant other relationship stress, field-dependence, and an 80-min. workpace predicted data-entry errors. Mistakes in product selection were associated with low GPA, high social stress, the NASA Task Load Index dimension of less concern with performing well, and a 70-min. workpace. Relationship of data to corresponding information in the pharmacy literarure and to assumptions of a cognitive-systems performance model was discussed.
APA, Harvard, Vancouver, ISO, and other styles
3

Istiqomah, Istiqomah, Choirul Anam, and Faris Zulkhilmi. "Efektivitas Macam Metode Aplikasi Pupuk Organik Cair dan Dosis Pupuk Kandang Ayam Terhadap Peningkatan Produksi Cabai Rawit (Capsicum frutescens L.)." AGRORADIX : Jurnal Ilmu Pertanian 4, no. 1 (December 29, 2020): 24–34. http://dx.doi.org/10.52166/agroteknologi.v4i1.2118.

Full text
Abstract:
Penelitian ini dilaksanakan di Desa Karang tawar, Kecamatan Laren, Kabupaten Lamongan. Ketinggian tempat ± 6 meter di atas permukaan laut (mdpl). Waktu penelitian dilaksanakan pada bulan Maret sampai Juni 2020. Penelitian ini menggunakan Metode Rancangan Acak Kelompok (RAK) yang disusun secara faktorial dengan dua faktor perlakuan yaitu Macam metode aplikasi POC Nasa (M) dan Dosis pupuk kandang ayam (D). Faktor Metode aplikasi terdiri 3 perlakuan yaitu: Tanpa aplikasi (MI), disemprot (M2), disiram (M3). Dosis Pupuk kandang Ayam terdiri dari 3 level yaitu: Pemberian 6 ton/ha (D1), Pemberian 10 ton/ha (D2), dan Pemberian 14 ton/ha (D3). Indikator pertumbuhan dan produksi yang diamati meliputi: Tinggi tanaman, Diameter batang, Jumlah Cabang, Banyak buah pertanaman dan Berat buah pertanaman. Pengamatan dilaksanakan mulai umur 14,28 hari dan dilanjut 42 hari sekali. Data hasil dari penelitian sejak tanaman berumur 14 hari hingga akhir pengamatan, dianalisa dengan analisa sidik ragam dan dilanjutkan dengan Uji BNT 5%. Hasil penelitian menunjukkan bahwa terdapat interaksi antara perlakuan macam metode aplikasi POC Nasa. Kombinasi perlakuan terbaik adalah D3M3 (pemberian pupuk 14 ton/ha) pada parameter tinggi tanaman dan Diameter batang. Perlakuan macam metode aplikasi POC Nasa hampir seluruh parameter pengamatan. Dosis pupuk kandang ayam berpengaruh terhadap tinggi tanaman, jumlah Buah, jumlah Cabang, banyak Buah dan Berat buah.
APA, Harvard, Vancouver, ISO, and other styles
4

Mosquera Abello, Carlos Andrés, Armando Javier Rojas Salazar, and Volney Enrique Bello Avena. "Septorrinoplastia y su influencia en el acondicionamiento nasa." ACTA DE OTORRINOLARINGOLOGÍA & CIRUGÍA DE CABEZA Y CUELLO 45, no. 3 (September 24, 2018): 165–70. http://dx.doi.org/10.37076/acorl.v45i3.344.

Full text
Abstract:
Introducción: La septorrinoplastia funcional y estética primaria es un procedimiento común en cirugía plástica facial. Objetivo: Analizar de forma subjetiva y objetiva el impacto de la cirugía en el acondicionamiento nasal en pacientes con deformidades nasales externas e internas. Diseño: Cuasi-experimental. Materiales y métodos: Se incluyeron 42 pacientes este estudio, se midieron la temperatura y humedad del ambiente y la intranasal del paciente, además del grado de obstrucción nasal antes y doce meses después de la cirugía; se utilizó una escala subjetiva de obstrucción nasal y un termohigrómetro con sensor externo para las mediciones intranasales. Resultados: Los valores de temperatura, humedad postoperatorias y la escala subjetiva de obstrucción nasal fueron de manera significativa estadísticamente mayores en comparación con las preoperatorias (p<0,05). Conclusiones: De acuerdo con los resultados de este estudio, los pacientes tienen un beneficio general gracias a una mejoría del acondicionamiento del aire nasal inspirado posterior a la realización de una septorrinoplastia funcional y estética primaria.
APA, Harvard, Vancouver, ISO, and other styles
5

Zaidat, Osama O., Alicia C. Castonguay, Rishi Gupta, Chung-Huan J. Sun, Coleman Martin, William E. Holloway, Nils Mueller-Kronast, et al. "North American Solitaire Stent Retriever Acute Stroke registry: post-marketing revascularization and clinical outcome results." Journal of NeuroInterventional Surgery 10, Suppl 1 (July 2018): i45—i49. http://dx.doi.org/10.1136/neurintsurg-2013-010895.rep.

Full text
Abstract:
BackgroundLimited post-marketing data exist on the use of the Solitaire FR device in clinical practice. The North American Solitaire Stent Retriever Acute Stroke (NASA) registry aimed to assess the real world performance of the Solitaire FR device in contrast with the results from the SWIFT (Solitaire with the Intention for Thrombectomy) and TREVO 2 (Trevo versus Merci retrievers for thrombectomy revascularization of large vessel occlusions in acute ischemic stroke) trials.MethodsThe investigator initiated NASA registry recruited North American sites to submit retrospective angiographic and clinical outcome data on consecutive acute ischemic stroke (AIS) patients treated with the Solitaire FR between March 2012 and February 2013. The primary outcome was a Thrombolysis in Myocardial Ischemia (TIMI) score of ≥2 or a Treatment in Cerebral Infarction (TICI) score of ≥2a. Secondary outcomes were 90 day modified Rankin Scale (mRS) score, mortality, and symptomatic intracranial hemorrhage.Results354 patients underwent treatment for AIS using the Solitaire FR device in 24 centers. Mean time from onset to groin puncture was 363.4±239 min, mean fluoroscopy time was 32.9±25.7 min, and mean procedure time was 100.9±57.8 min. Recanalization outcome: TIMI ≥2 rate of 83.3% (315/354) and TICI ≥2a rate of 87.5% (310/354) compared with the operator reported TIMI ≥2 rate of 83% in SWIFT and TICI ≥2a rate of 85% in TREVO 2. Clinical outcome: 42% (132/315) of NASA patients demonstrated a 90 day mRS ≤2 compared with 37% (SWIFT) and 40% (TREVO 2). 90 day mortality was 30.2% (95/315) versus 17.2% (SWIFT) and 29% (TREVO 2).ConclusionsThe NASA registry demonstrated that the Solitaire FR device performance in clinical practice is comparable with the SWIFT and TREVO 2 trial results.
APA, Harvard, Vancouver, ISO, and other styles
6

Hansell, R. A., S. C. Tsay, Q. Ji, N. C. Hsu, M. J. Jeong, S. H. Wang, J. S. Reid, K. N. Liou, and S. C. Ou. "An Assessment of the Surface Longwave Direct Radiative Effect of Airborne Saharan Dust during the NAMMA Field Campaign." Journal of the Atmospheric Sciences 67, no. 4 (April 1, 2010): 1048–65. http://dx.doi.org/10.1175/2009jas3257.1.

Full text
Abstract:
Abstract In September 2006, NASA Goddard’s mobile ground-based laboratories were deployed to Sal Island in Cape Verde (16.73°N, 22.93°W) to support the NASA African Monsoon Multidisciplinary Analysis (NAMMA) field study. The Atmospheric Emitted Radiance Interferometer (AERI), a key instrument for spectrally characterizing the thermal IR, was used to retrieve the dust IR aerosol optical depths (AOTs) in order to examine the diurnal variability of airborne dust with emphasis on three separate dust events. AERI retrievals of dust AOT are compared with those from the coincident/collocated multifilter rotating shadowband radiometer (MFRSR), micropulse lidar (MPL), and NASA Cloud–Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) sensors. The retrieved AOTs are then inputted into the Fu–Liou 1D radiative transfer model to evaluate local instantaneous direct longwave radiative effects (DRELW) of dust at the surface in cloud-free atmospheres and its sensitivity to dust microphysical parameters. The top-of-atmosphere DRELW and longwave heating rate profiles are also evaluated. Instantaneous surface DRELW ranges from 2 to 10 W m−2 and exhibits a strong linear dependence with dust AOT yielding a DRELW of 16 W m−2 per unit dust AOT. The DRELW is estimated to be ∼42% of the diurnally averaged direct shortwave radiative effect at the surface but of opposite sign, partly compensating for the shortwave losses. Certainly nonnegligible, the authors conclude that DRELW can significantly impact the atmospheric energetics, representing an important component in the study of regional climate variation.
APA, Harvard, Vancouver, ISO, and other styles
7

Tac, Vu Van. "Variability of sea surface chlorophyll_a concentration in the South Vietnam coastal waters related to enso phenomenon." VIETNAM JOURNAL OF EARTH SCIENCES 42, no. 1 (January 15, 2020): 67–74. http://dx.doi.org/10.15625/0866-7187/42/1/14759.

Full text
Abstract:
This paper focuses on analyzing the monthly averaged sea surface chlorophyll_a concentration data for 16 years (Jul. 2002 ÷ Sep. 2018), a remote sensing data product of the US National Aeronautics and Space Administration (US NASA), the analyzed results have shown that each occurrence of ENSO phenomenon greatly affects the fluctuation of chlorophyll_a concentration in the South Vietnam‘s coastal waters (SVNC). The monthly averaged chlorophyll_a concentration varies from 0.5 [mg/m3] to 1.1 [mg/m3] (equivalent to 22.4% ÷ 49.3%), while the monthly averaged fluctuation of chlorophyll_a concentration between months is only 0.22 [mg/m3] (equivalent to 9.88%). These fluctuations have a great impact on nutritional resources as well as water quality because chlorophyll_a is a pigment in plankton, which is a criterion to assess the "rich or poor" of nutrition source in seawater. The results of this study are considered as a "small piece" in the overall picture of the impact of ENSO phenomenon on global climate change.
APA, Harvard, Vancouver, ISO, and other styles
8

Загидуллин, А. А., Н. К. Петрова, В. С. Усанин, and Ю. А. Нефедьев. "Анализ орбитальных теорий для построения численной теории физической либрации Луны." Известия Крымской астрофизической обсерватории 114, no. 1 (March 1, 2018): 37. http://dx.doi.org/10.31059/izcrao-vol114-iss1-pp37-42.

Full text
Abstract:
При построении численной теории физической либрации перед нами встала задача сравнения численной и аналитической теорий орбитального движения Луны. В ходе исследования нам было важно понять, как различия в точности описания движения центра масс скажутся на поведении либрации. На данный момент мы представляем результаты первого этапа сравнения, а именно: описание поведения во времени различий между двумя типами орбитальных теорий. Нами была использована аналитическая теория Гутцвиллера и Шмидта, построенная в рамках главной проблемы, и современная численная теория DE431 JPL NASA, учитывающая большое количество факторов, выходящих за рамки главной проблемы, которые было бы сложно или даже невозможно учесть при получении аналитического решения. Произведя необходимые редукции при приведении обеих теорий к единой системе отсчета, мы сравнили оба решения на интервале в 800 лет. В итоге мы получили, что амплитуда в долготе за этот период не превосходит 80 угловых секунд, а в широте 10 угловых секунд. Основным источником расхождений являются эффекты, не учитываемые в главной проблеме, такие как: планетные возмущения, движение плоскости эклиптики, сжатие Земли, приливные эффекты и эффекты общей теории относительности.
APA, Harvard, Vancouver, ISO, and other styles
9

Roesch, J. Richard. "Handgrip Strength with the Bare Hand and in the NASA Spacesuit Glove." Proceedings of the Human Factors Society Annual Meeting 31, no. 7 (September 1987): 786–90. http://dx.doi.org/10.1177/154193128703100722.

Full text
Abstract:
This study examined handgrip strength with the bare and spacesuit-gloved hand, in three hand and two elbow positions. Sixteen subjects from the suited-subject pool at NASA/Johnson Space Center gripped a hand dynamometer encased in a vacuum chamber designed to simulate the pressure differential of the spacesuit in space. With the bare hand (at one atmosphere), there was an effect for hand position and a hand-position x elbow-position interaction. With the spacesuit-gloved hand, there was only an effect for hand position. Two different pressure differentials (psid) were used: the glove at 0.5 psid was responsible for a 35% grip decrement (when compared to bare handgrip); the glove at 4.3 psid (normal operating pressure) was responsible for a 42% grip decrement. Bare and gloved-handgrip were positively correlated with hand size, body weight, height, and forearm circumference. Post-hoc, subjects were grouped by hand size; the four subjects in the XL hand-size group lost an average of 17% in grip in the glove at 4.3 psid (when compared to the glove at 0.5 psid); the L group lost 12%; the M group lost 9%; and the S hand-size group lost less than 1%. The larger the hand, the greater was the grip strength decrement due to increased pressure in the glove.
APA, Harvard, Vancouver, ISO, and other styles
10

McCormack, J. P., S. D. Eckermann, L. Coy, D. R. Allen, Y. J. Kim, T. Hogan, B. Lawrence, et al. "NOGAPS-ALPHA model simulations of stratospheric ozone during the SOLVE2 campaign." Atmospheric Chemistry and Physics 4, no. 9/10 (December 2, 2004): 2401–23. http://dx.doi.org/10.5194/acp-4-2401-2004.

Full text
Abstract:
Abstract. This paper presents three-dimensional prognostic O3 simulations with parameterized gas-phase photochemistry from the new NOGAPS-ALPHA middle atmosphere forecast model. We compare 5-day NOGAPS-ALPHA hindcasts of stratospheric O3 with satellite and DC-8 aircraft measurements for two cases during the SOLVE II campaign: (1) the cold, isolated vortex during 11-16 January 2003; and (2) the rapidly developing stratospheric warming of 17-22 January 2003. In the first case we test three different photochemistry parameterizations. NOGAPS-ALPHA O3 simulations using the NRL-CHEM2D parameterization give the best agreement with SAGE III and POAM III profile measurements. 5-day NOGAPS-ALPHA hindcasts of polar O3 initialized with the NASA GEOS4 analyses produce better agreement with observations than do the operational ECMWF O3 forecasts of case 1. For case 2, both NOGAPS-ALPHA and ECMWF 114-h forecasts of the split vortex structure in lower stratospheric O3 on 21 January 2003 show comparable skill. Updated ECMWF O3 forecasts of this event at hour 42 display marked improvement from the 114-h forecast; corresponding updated 42-hour NOGAPS-ALPHA prognostic O3 fields initialized with the GEOS4 analyses do not improve significantly. When NOGAPS-ALPHA prognostic O3 is initialized with the higher resolution ECMWF O3 analyses, the NOGAPS-ALPHA 42-hour lower stratospheric O3 fields closely match the operational 42-hour ECMWF O3 forecast of the 21 January event. We find that stratospheric O3 forecasts at high latitudes in winter can depend on both model initial conditions and the treatment of photochemistry over periods of 1-5 days. Overall, these results show that the new O3 initialization, photochemistry parameterization, and spectral transport in the NOGAPS-ALPHA NWP model can provide reliable short-range stratospheric O3 forecasts during Arctic winter.
APA, Harvard, Vancouver, ISO, and other styles
More sources

Dissertations / Theses on the topic "NASA 42"

1

Bruno, Liam T. "Three Axis Attitude Control System Design and Analysis Tool Development for the Cal Poly CubeSat Laboratory." DigitalCommons@CalPoly, 2020. https://digitalcommons.calpoly.edu/theses/2288.

Full text
Abstract:
The Cal Poly CubeSat Laboratory (CPCL) is currently facing unprecedented engineering challenges—both technically and programmatically—due to the increasing cost and complexity of CubeSat flight missions. In responding to recent RFPs, the CPCL has been forced to find commercially available solutions to entire mission critical spacecraft subsystems such as propulsion and attitude determination & control, because currently no in-house options exist for consideration. The commercially available solutions for these subsystems are often extremely expensive and sometimes provide excessively good performance with respect to mission requirements. Furthermore, use of entire commercial subsystems detracts from the hands-on learning objectives of the CPCL by removing engineering responsibility from students. Therefore, if these particular subsystems can be designed, tested, and integrated in-house at Cal Poly, the result would be twofold: 1) the space of missions supportable by the CPCL under tight budget constraints will grow, and 2) students will be provided with unique, hands-on guidance, navigation, and control learning opportunities. In this thesis, the CPCL’s attitude determination and control system design and analysis toolkit is significantly improved to support in-house ADCS development. The toolkit—including the improvements presented in this work—is then used to complete the existing, partially complete CPCL ADCS design. To fill in missing gaps, particular emphasis is placed on guidance and control algorithm design and selection of attitude actuators. Simulation results show that the completed design is competitive for use in a large class of small satellite missions for which pointing accuracy requirements are on the order of a few degrees.
APA, Harvard, Vancouver, ISO, and other styles
2

Piovesana, Ana Maria Sedrez Gonzaga 1952. "Hemiparesia congenita : estudo de 42 crianças." [s.n.], 1993. http://repositorio.unicamp.br/jspui/handle/REPOSIP/311120.

Full text
Abstract:
Orientador : Maria Valeriana Leme de Moura Ribeiro
Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Ciências Médicas
Made available in DSpace on 2018-07-18T10:53:16Z (GMT). No. of bitstreams: 1 Piovesana_AnaMariaSedrezGonzaga_M.pdf: 10852588 bytes, checksum: 17fbf4f71c978cfd097b4096b6a10a97 (MD5) Previous issue date: 1993
Resumo: Hemiparesia congênita (HC) é uma forma de paralisia cerebral (PC) onde um hemicorpo é comprometido por etiologia pré ou pós perinatal. Selecionou-se 42 crianças com HC provenientes dos ambulatórios do Hospital das Clínicas da UNICAMP, para avaliação e acompanhamento prospectivo. Avaliou-se os dados da anamnese, do exame neurológico e dos exames complementares, interrelacionando-os a fim de definir grupos de risco e suas associações.......Observação: O resumo, na íntegra, poderá ser visualizado no texto completo da tese digital.
Abstract: Congenital Hemiparesis (CH) is a form of cerebral palsy (CP) were only one side is affected. The etiology is allways pre or perinatal. We have selected 42 cases from UNICAMP General hospital for evaluation and follow-up. The purpose of tke study was to analyse the clinical history, the clinical evaluation, electroencepkalography (EEG) and neuroraciological examinations, ano to correlate the pathogenic eriods, aetiological factors ano clinical paremeters to neuroradiology. ...Note: The complete abstract is available with the full electronic digital thesis or dissertations.
Mestrado
Mestre em Neurociencias
APA, Harvard, Vancouver, ISO, and other styles
3

Franchino, Giuseppe <1980&gt. "I tumori naso sinusali: stima dell'incidenza e valutazione dell'esposizione a cancerogeni professionali in Emilia-Romagna." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2016. http://amsdottorato.unibo.it/7599/.

Full text
Abstract:
Introduzione I Tumori Naso-Sinusali (TuNS) sono neoplasie a bassa incidenza ma, per gli istotipi epiteliali, ad elevata frazione eziologica professionale. Il Registro Tumori Naso-Sinusale (ReNaTuNS) è stato istituito in Italia nel 2008, mentre in Emilia Romagna, il relativo Centro Operativo Regionale (COR) nel 2012. Obiettivo dello studio: • effettuare una revisione della letteratura scientifica sui cancerogeni associati all'insorgenza di TuNS; • descrivere l' attività di costruzione del COR in Emilia Romagna; • stimare l'incidenza di TuNS in Emilia Romagna; • analizzare i questionari somministrati ai casi incidenti al fine di individuare l'eventuale esposizione professionale a cancerogeni. Metodi • La revisione della letteratura è stata svolta utilizzando i database Cochrane Library e Medline. • la descrizione delle attività di costruzione del COR è avvenuta attraverso l’analisi delle attività svolte, dei documenti prodotti e dei dati raccolti; • il calcolo dei tassi di incidenza (anni 2007-2011) è avvenuto utilizzando la popolazione standard italiana di riferimento censita nel 2011; • l'analisi dei questionari è avvenuta tramite un panel di esperti Risultati • La revisione della letteratura ha confermato un’associazione certa tra polveri di legno e cuoio e TuNS, mentre resta da definire l'associazione con altre sostanze di frequente uso nelle attività produttive. • Il COR ha individuato 253 casi di TuNS, incidenti dal 2007 in poi, e ha definito l' eventuale esposizione professionale per 62 casi. • L'incidenza di TuNS stimata in regione è di 1,0 (per 100.000), mentre per la popolazione maschile e femminile rispettivamente dell' 1,3 e dello 0,8 (per 100.000). • L’analisi dei questionari ha rilevato un'esposizione professionale nel 57,9% degli intervistati. Conclusioni L'incidenza di TuNS in Emilia Romagna è tra le più elevate a livello nazionale, in particolare per il genere femminile. L'analisi dei questionari conferma l'elevata frazione eziologica professionale della patologia.
Introduction Sinonasal cancer (SNC) are cancer with low incidence. The epithelial form has an high occupational ethiological fraction. Sinonasal cancer registry (SCR) in Italy has been established in 2008, while the Regional Operting Center (ROC) of Emilia Romagna in 2012. Objectives: • to perform a review of the scientific literature on the carcinogenic agents associated with SNC; • to describe the main activities of construction of the ROC in Emilia Romagna • to estimate the incidence of SNC in Emilia Romagna; • to analyze the questionnaires administered to cases of epithelial SNC to assess the possible occupational exposure Methods • The literature review was performed using Cochrane Library e Medline databases, • In order to describe the main activities of construction of the ROC in Emilia Romagna has been conducted an analysis of the documents and data collected, • Incidence rate (2007-2011) of SNC in Emilia Romagna was estimated using italian standard reference population census in 2011; • The questionnaires were analyzed by a panel of experts Results • The review confirmed an association with sufficient evidence between wood dust and leather dust and SNC. There is an association for other carcinogenic agents but the evidence is limited; • The ROC identified 253 cases of SNC and defined the occupational exposure for 62 cases. • Incidence rate of SNC in Emilia Romagna was 1,0 (per 100.000), 1,3 among men and 0,8 among women; • The occupational exposure was indentified by 57,9% of respondents. Conclusion Data show an incidence of SNC very hig in Emilia Romagna especially among women. The analysis of questionnaires confirms an high occupational ethiological fraction of SNC.
APA, Harvard, Vancouver, ISO, and other styles
4

Soares, Alexandre Learth. "Instilação nasal de LPS ou suco gástrico como fator exacerbador da inflamação pulmonar ocasionada pela isquemia e reperfusão intestinal em camundongos." Universidade de São Paulo, 2009. http://www.teses.usp.br/teses/disponiveis/42/42136/tde-06102009-151646/.

Full text
Abstract:
A isquemia e reperfusão intestinal (I/R-i) é relevante fator para o desenvolvimento da síndrome do desconforto respiratório agudo (SDRA). A lesão tecidual decorrente da I/R-i pode ser local e em órgãos distante do sitio isquêmico, notadamente o pulmão. Indivíduos submetidos à isquemia intestinal ao tornarem-se vulneráveis, desenvolvem resposta exacerbada a estímulos inflamatórios secundários constituindo assim a percepção de lesão decorrente de uma dupla agressão. Neste estudo desenvolvemos modelo murino de dupla agressão pulmonar ocasionada pela I/R-i seguida de estímulo da instilação nasal de LPS ou de suco gástrico (SG). A fase de caracterização do modelo de I/R-i revelou aumento de IL-6, G-CSF, KC, IP-10 e MCP-1, mas não de TNF-a no soro e em homogeneizados de pulmão e intestino. Anticorpos anti TNF-a e o etanercepte falharam em inibir o aumento de MPO pulmonar e intestinal após a I/R-i. A instilação nasal de LPS após a I/R-i aumentou a atividade pulmonar de MPO e exacerbou a permeabilidade vascular pulmonar. Neste caso, aminoguanidina ou a vimblastina reverterem o aumento da permeabilidade vascular, sugerindo a participação conjunta de neutrófilos e óxido nítrico no processo lesivo causado pela dupla agressão. A instilação nasal de SG induziu aumento inicial (2h) de MPO pulmonar seguido de influxo de neutrófilos (24h) para o espaço alveolar. Tal processo foi acompanhado por expressão inicial e transiente de TNF-a no LBA e contrabalanceada por IL-10. A resposta inflamatória aumentada de camundongos IL-10 KO à instilação de suco gástrico mostra o papel fundamental desta citocina do controle da inflamação. O rolipram ou o composto PKF 241-466 (inibidores de TNF-a) reduziram a inflamação pulmonar induzida pelo SG. A instilação de SG após a I/R-i (I/R-i +SG) exacerbou o aumento da permeabilidade vascular pulmonar. Os dados apresentados sugerem que a exposição do organismo ao trauma intestinal torna o pulmão suscetível a um estímulo secundário como o LPS e o suco gástrico. Visto a gama de estímulos inflamatórios a que indivíduos internados em unidades de terapia intensiva podem ser submetidos, os resultados deste estudo podem contribuir para a compreensão dos mecanismos reguladores do recrutamento de neutrófilos e geração de mediadores inflamatórios na síndrome do desconforto respiratório agudo.
Intestinal ischemia and reperfusion (I/R) is implicated as a prime initiating event in the development of systemic inflammatory syndrome and Acute Respiratory Distress Syndrome (ARDS). Several studies pointed the possibility of massive systemic inflammatory events rendering the lungs more susceptible to an exacerbated inflammatory response, the so called two-hit hypothesis. In this way, minor local inflammatory stimuli could be a trigger for ARDS. In this study we investigated the effects of low-dose LPS or gastric juice (GJ) administered by nasal instillation to mice previously submitted to intestinal I/R. Our data showed that i-I/R alone induced histological signs of edema in lung as well as an increase of lung MPO activity and IL-6, G-CSF, KC, IP-10 and MCP-1 levels. Nasal instillation of LPS following i-I/R increased lung MPO activity and exacerbated lung vascular permeability. In this case, aminoguanidine or vinblastine blocked the increase of vascular permeability, suggesting the role of neutrophils and nitric oxide in injury induced by the two-hit stimuli. Instillation of GJ induced an initial (2h) increase of lung MPO followed by the influx of neutrophils (24h) to the alveolar space. Such process was followed by the transient expression of TNF-a in BAL and balanced by IL-10. The exacerbated inflammatory response of IL-10 KO mice to GJ instillation shows the importance of this cytokine in the control of the inflammation in such model. Treatment with rolipram or PKF 241-466 compound (TNF-a inhibitors) reduced lung inflammation induced by GJ. Nasal instillation of GJ after i-I/R exacerbated the increase in lung vascular permeability. The data shown suggest that the exposition of the organism to mesenteric trauma primes the host organism to a secondary inflammatory stimulus such as LPS or gastric juice. Considering the possible multiple insults to lung to which patients in intensive care units are submitted, the results of this study might contribute to the understanding of the regulatory mechanisms of neutrophils and generation of inflammatory mediators in the context of ARDS.
APA, Harvard, Vancouver, ISO, and other styles
5

Júnior, João Antonio Gimenes. "Papel dos hormônios sexuais femininos na inflamação pulmonar aguda e na reatividade das vias aéreas após instilação nasal de LPS em camundongos." Universidade de São Paulo, 2013. http://www.teses.usp.br/teses/disponiveis/42/42136/tde-17062014-092827/.

Full text
Abstract:
Lesão pulmonar aguda é caracterizada por infiltrado de neutrófilos no pulmão, edema, lesão alveolar difusa e alteração da reatividade das vias aéreas. Evidências clínicas e experimentais sugerem que os hormônios sexuais femininos (HSF) modulam a inflamação. Nesse estudo camundongos fêmeas C57BL/6 foram ovariectomizados (OVx) ou falsamente operados, com ovários mantidos (Sham). Após 7 dias foi realizada instilação nasal de LPS (ou salina como controle). Após 4 ou 24 h os experimentos foram conduzidos. Os resultados obtidos 24 h após o LPS mostram aumento de neutrófilos, IL-1b e de óxido nítrico (NO) e redução de IL-10 no pulmão dos animais OVx em relação aos Sham. Também foi observada redução da reatividade traqueal e da resistência e elastância pulmonar dos animais OVx. O tratamento dos animais OVx com 17b-estradiol ou progesterona antes do LPS reverteram esses efeitos. Os dados mostram que 4 h após o LPS a OVx não altera a inflamação e a reatividade das vias aéreas. Pode-se concluir nesse modelo experimental que os HSF exerçam papel de proteção ao organismo.
Acute lung injury is characterized by lung neutrophil infiltration, edema, diffuse alveolar damage and changes in airway reactivity. Clinical and experimental evidences suggest that the female sex hormones (FSH) modulate the inflammation. In this study, female mice C57BL/6 were ovariectomized (OVx) or not (Sham). After 7 days, LPS or saline (as control) were intranasally instillated. After 4 or 24 h the experiments were carried. We observed, 24 h after LPS, increase in neutrophil, IL-1b and nitric oxide (NO) and reduction of IL-10 in the lungs of OVx compared to Sham. We also noted reduced tracheal reactivity and lung resistance and elastance in OVx animals. Treatment of OVx with 17b-estradiol or progesterone before LPS reversed these effects. The data show that 4 h after LPS, the OVx does not promote inflammation and airway reactivity. We can conclude that in our experimental model, FSH exert protective role.
APA, Harvard, Vancouver, ISO, and other styles
6

Denner, Nana-Daniela [Verfasser]. "Der Einfluss unterschiedlicher Präparationsformen auf die Randspaltqualität von keramischen Teilkronen / vorgelegt von Nana-Daniela Denner." 2003. http://d-nb.info/967997593/34.

Full text
APA, Harvard, Vancouver, ISO, and other styles

Books on the topic "NASA 42"

1

Cowing, Keith L., and Frank Sietzen Jr. New Moon Rising: The Making of America's New Space Vision and the Remaking of NASA: Apogee Books Space Series 42 (Apogee Books Space Series). Collector's Guide Publishing Inc, 2004.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
2

Laforet, Carmen. Carmen Laforet: Nada (Coleccion Destinolibro; V. 42). AIMS International Books, 1996.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
3

Lyndon B. Johnson Space Center. Systems Engineering Division. and Chrysler Corporation. Electronics Products Division. Michoud Engineering Office. Data Management Services., eds. Results of A M = 5.3 heat transfer test of the integrated vehicle using phase-change paint techniques on the 0.0175-scale model 56-OTS in the NASA/AMES Research Center 3.5-foot hypersonic wind tunnel (IH-42). Houston, Tex: Systems Engineering Division, Johnson Space Center, National Aeronautics and Space Administration, 1985.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
4

Lyndon B. Johnson Space Center. Systems Engineering Division. and Chrysler Corporation. Electronics Products Division. Michoud Engineering Office. Data Management Services., eds. Results of A M = 5.3 heat transfer test of the integrated vehicle using phase-change paint techniques on the 0.0175-scale model 56-OTS in the NASA/AMES Research Center 3.5-foot hypersonic wind tunnel (IH-42). Houston, Tex: Systems Engineering Division, Johnson Space Center, National Aeronautics and Space Administration, 1985.

Find full text
APA, Harvard, Vancouver, ISO, and other styles

Book chapters on the topic "NASA 42"

1

"42. El Niño." In A Vineyard in Napa, 222–25. University of California Press, 2019. http://dx.doi.org/10.1525/9780520954120-046.

Full text
APA, Harvard, Vancouver, ISO, and other styles
2

"42 The Crooked Nasal Tip." In Rhinoplasty, edited by Anthony P. Sclafani. Stuttgart: Georg Thieme Verlag, 2015. http://dx.doi.org/10.1055/b-0035-104274.

Full text
APA, Harvard, Vancouver, ISO, and other styles
3

"42 Innere Nase und Nasennebenhöhlen – Blutungen." In Referenz HNO-Heilkunde, edited by Orlando Guntinas-Lichius, Jens Peter Klußmann, and Stephan Lang. Stuttgart: Georg Thieme Verlag KG, 2021. http://dx.doi.org/10.1055/b-0041-181634.

Full text
APA, Harvard, Vancouver, ISO, and other styles
4

Galán, José M. "Ahmose-Sapair in Dra Abu el-Naga:." In Proceedings of the XI International Congress of Egyptologists, Florence, Italy 23-30 August 2015, 215–21. Archaeopress Publishing Ltd, 2017. http://dx.doi.org/10.2307/j.ctv177tjnf.42.

Full text
APA, Harvard, Vancouver, ISO, and other styles
5

"Index." In Pediatric Nasal and Sinus Disorders, 593–615. CRC Press, 2005. http://dx.doi.org/10.1201/b14160-42.

Full text
APA, Harvard, Vancouver, ISO, and other styles
6

Corbridge, Rogan, and Nicholas Steventon. "Common methods of presentation." In Oxford Handbook of ENT and Head and Neck Surgery, 31–52. Oxford University Press, 2009. http://dx.doi.org/10.1093/med/9780199550791.003.03.

Full text
Abstract:
Hoarse voice 32 Epistaxis (nosebleed) 33 Dysphagia (swallowing difficulty) 34 A feeling of a lump in the throat 35 A lump in the neck 36 Mouth or tongue ulcer 38 Stridor 40 Facial nerve palsy 42 Nasal obstruction 43 The discharging ear 44 Dizziness and vertigo ...
APA, Harvard, Vancouver, ISO, and other styles
7

Horswell, Bruce. "Excision of skin lesions and orbital and nasal reconstruction." In Operative Oral and Maxillofacial Surgery Second edition, 291–306. CRC Press, 2010. http://dx.doi.org/10.1201/b13386-42.

Full text
APA, Harvard, Vancouver, ISO, and other styles
8

"42. The Confucian Monarchy of Nara Japan." In Religions of Asia in Practice, 660–65. Princeton University Press, 2002. http://dx.doi.org/10.1515/9780691188140-049.

Full text
APA, Harvard, Vancouver, ISO, and other styles
9

"42 Surgery of the Bony Nasal Vault." In Facial Plastic and Reconstructive Surgery, edited by Ira D. Papel. Stuttgart: Georg Thieme Verlag, 2009. http://dx.doi.org/10.1055/b-0034-73260.

Full text
APA, Harvard, Vancouver, ISO, and other styles
10

González-Maciel, Angélica, Rafael Reynoso-Robles, Ricardo Torres-Jardón, Partha S. Mukherjee, and Lilian Calderón-Garcidueñas. "Combustion-Derived Nanoparticles in Key Brain Target Cells and Organelles in Young Urbanites: Culprit Hidden in Plain Sight in Alzheimer’s Disease Development." In Advances in Alzheimer’s Disease. IOS Press, 2021. http://dx.doi.org/10.3233/aiad210005.

Full text
Abstract:
Millions of children and young adults are exposed to fine particulate matter (PM2.5) and ozone, associated with Alzheimer’s disease (AD) risk. Mexico City (MC) children exhibit systemic and brain inflammation, low cerebrospinal fluid (CSF) Aβ1-42, breakdown of nasal, olfactory, alveolar-capillary, duodenal, and blood-brain barriers, volumetric and metabolic brain changes, attention and short-term memory deficits, and hallmarks of AD and Parkinson’s disease. Airborne iron-rich strongly magnetic combustion-derived nanoparticles (CDNPs) are present in young urbanites’ brains. Using transmission electron microscopy, we documented CDNPs in neurons, glia, choroid plexus, and neurovascular units of young MC residents versus matched clean air controls. CDNPs are associated with pathology in mitochondria, endoplasmic reticulum (ER), mitochondria-ER contacts (MERCs), axons,and dendrites. There is a significant difference in size and numbers between spherical CDNPs (>85%) and the angular, euhedral endogenous NPs (<15%). Spherical CDNPs (dogs 21.2 ± 7.1 nm in diameter versus humans 29.1 ± 11.2 nm, p = 0.002) are present in neurons, glia, choroid plexus, endothelium, nasal and olfactory epithelium, and in CSF at significantly higher in numbers in MC residents (p < 0.0001). Degenerated MERCs, abnormal mitochondria, and dilated ER are widespread, and CDNPs in close contact with neurofilaments, glial fibers, and chromatin are a potential source for altered microtubule dynamics, mitochondrial dysfunction, accumulation and aggregation of unfolded proteins, abnormal endosomal systems, altered insulin signaling, calcium homeostasis, apoptotic signaling, autophagy, and epigenetic changes. Highly oxidative, ubiquitous CDNPs constitute a novel path into AD pathogenesis. Exposed children and young adults need early neuroprotection and multidisciplinary prevention efforts to modify the course of AD at early stages.
APA, Harvard, Vancouver, ISO, and other styles

Conference papers on the topic "NASA 42"

1

Landes, Scott, Trupti Suresh, Anamika Prasad, Todd Letcher, Paul Gradl, and David Ellis. "Investigation of Additive Manufactured GRCop-42 Alloy Developed by Directed Energy Deposition Methods." In ASME 2020 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2020. http://dx.doi.org/10.1115/imece2020-24400.

Full text
Abstract:
Abstract GRCop is an alloy family constructed of copper, chromium, and niobium and was developed by NASA for high heat flux applications. GRCop-alloys were specifically formulated for the requirements in channel-cooled main combustion chambers allowing for repeat use in high heat flux environments [1]. GRCop-84 was evolved using additive manufacturing techniques under a NASA development program. To further increase thermal conductivity while maintaining material strength characteristics, the percentage of alloying elements were cut in half and GRCop-42 was developed. In recent years, NASA has successfully additively manufactured GRCop-42 with comparable material characteristics to extruded GRCop-42 using a Laser Powder Bed Fusion (L-PBF) process. Benefits of this process include fabrication of intricate internal cooling channels as well as a decrease in manufacturing time. However, there are some large disadvantages in using this process. The nature of the powder bed process imposes a strict volume constraint as well as an excessive amount of material inventory required. A Directed Energy Deposition (DED) process addresses these limitations while also speeding up the manufacturing process. With little data on how DED performs with GRCop-42, an investigation into the mechanical properties was conducted. More specifically, Blown Powder Directed Energy Deposition (BPD), was used to compare material properties to that of the L-PBF manufactured GRCop-42. The DED manufactured material was found to have less than 0.1% porosity. Tensile tests concluded that the DED manufactured GRCop-42 had lower tensile strengths at room temperature. The results point towards a process capable of producing fully dense parts capable of meeting mechanical strength requirements with some possible refinement of printing parameters.
APA, Harvard, Vancouver, ISO, and other styles
2

Povinelli, Louis A. "Validation of Viscous and Inviscid Computational Methods for Turbomachinery Components." In ASME 1986 International Gas Turbine Conference and Exhibit. American Society of Mechanical Engineers, 1986. http://dx.doi.org/10.1115/86-gt-42.

Full text
Abstract:
An assessment of several three-dimensional computer codes used at the NASA Lewis Research Center is presented. Four flow situations are examined, for which both experimental data and computational results are available. The four flows form a basis for the evaluation of the computational procedures. It was concluded that transonic rotor flow at peak efficiency conditions may be calculated with a reasonable degree of accuracy, whereas, off-design conditions are not accurately determined. Duct flows and turbine cascade flows may also be computed with reasonable accuracy whereas radial inflow turbine flow remains a challenging problem.
APA, Harvard, Vancouver, ISO, and other styles
3

Suresh, Trupti, Scott Landes, Todd Letcher, Anamika Prasad, Paul Gradl, and David Ellis. "Nanomechanical Characterization of Additive Manufactured GRCop-42 Alloy Developed by Directed Energy Deposition Methods." In ASME 2020 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2020. http://dx.doi.org/10.1115/imece2020-23382.

Full text
Abstract:
Abstract Propulsion applications such as combustion chambers and nozzles for liquid rocket engines require the use of unique materials with superior mechanical and thermal properties. GRCop-42 (Cu-4 wt.% Cr-2 wt.% Nb) is one such candidate material developed by NASA and is now being manufactured using additive manufacturing (AM) techniques. AM offers a unique processing environment different from traditional metal fabrication processes. This study characterized the mechanical and structural properties of as-deposited and heat-treated GRCop-42 manufactured with Blown Powder Directed Energy Deposition (BPD) based on preliminary testing. The materials were characterized using several techniques including surface profiling by laser microscopy, mechanical stiffness by instrumented indentation, crystal structure, residual stress measurements using XRD and residual XRD, and chemical composition and microstructural evaluation using SEM with EBSD. The results of the study are compared using the BPD techniques for samples in the as-deposited and heat-treated conditions.
APA, Harvard, Vancouver, ISO, and other styles
4

McLamore, Eric, Sybil Sharvelle, Kathy Banks, and Stephen Clark. "Abiotic Ammonia Mass Transfer in a Biotrickling Filter." In 10th Biennial International Conference on Engineering, Construction, and Operations in Challenging Environments and Second NASA/ARO/ASCE Workshop on Granular Materials in Lunar and Martian Exploration. Reston, VA: American Society of Civil Engineers, 2006. http://dx.doi.org/10.1061/40830(188)42.

Full text
APA, Harvard, Vancouver, ISO, and other styles
5

Blachut, J. "Buckling of Compound Spherical-Toroidal Shells under External Pressure." In 12th Biennial International Conference on Engineering, Construction, and Operations in Challenging Environments; and Fourth NASA/ARO/ASCE Workshop on Granular Materials in Lunar and Martian Exploration. Reston, VA: American Society of Civil Engineers, 2010. http://dx.doi.org/10.1061/41096(366)42.

Full text
APA, Harvard, Vancouver, ISO, and other styles
6

Agarwal, Ruchika, Anand Dhamarla, Sridharan R. Narayanan, Shraman N. Goswami, and Balamurugan Srinivasan. "Numerical Investigation on the Effect of Vortex Generator on Axial Compressor Performance." In ASME Turbo Expo 2014: Turbine Technical Conference and Exposition. American Society of Mechanical Engineers, 2014. http://dx.doi.org/10.1115/gt2014-25329.

Full text
Abstract:
The performance of the compressor blade is considerably influenced by secondary flow effects, like the cross flow on the end wall as well as corner flow separation between the wall and the blade. The present work is focused on the studying the effects of Vortex Generator (VG) on NASA Rotor 37 test case using Computational Fluid Dynamics (CFD). VG helps in controlling the inception of the stall by generating vortices and energizes the low momentum boundary layer flow which enhances the rotor performance. Three design configuration namely, Counter-rotating, Co-rotating and Plow configuration VG are selected based on the improved aerodynamic performance discussed in reference [1]. These VG are located at 90% span and 42% chord on suction side surface of the blade. Among the three configurations, the first configuration has greater impact on the end wall cross flow and flow deflection which resulted in enhanced numerical stall margin of 5.4% from baseline. The reasons for this numerical stall margin improvement are discussed in detail.
APA, Harvard, Vancouver, ISO, and other styles
7

Gan, Jiaye, Hong-Sik Im, and Ge-Cheng Zha. "Delayed Detached Eddy Simulation of Rotating Stall for a Full Annulus Transonic Axial Compressor Stage." In ASME Turbo Expo 2016: Turbomachinery Technical Conference and Exposition. American Society of Mechanical Engineers, 2016. http://dx.doi.org/10.1115/gt2016-57985.

Full text
Abstract:
This paper solves the filtered Navier-Stokes equations to simulate stall inception of NASA compressor transonic Stage 35 with delayed detached eddy simulation (DDES). A low diffusion E-CUSP Riemann solver with a 3rd order MUSCL scheme for the inviscid fluxes and a 2nd order central differencing for the viscous terms are employed. A full annulus of the rotor-stator stage is simulated with an interpolation sliding boundary condition (BC) to resolve the rotor-stator interaction. The tip clearance is fully gridded to accurately resolve tip vortices and their effect on stall inception. The DDES results show that the stall inception of Stage 35 is initialized by a weak harmonic disturbance with the length scales of the full annulus and grows rapidly with two emerging spike like disturbance. The two spike disturbances propagate in counter rotational direction with about 42% of rotor speed. The spike stall cells cover about 6 blades. They lead to two stall cells grown circumferentially and inwardly.
APA, Harvard, Vancouver, ISO, and other styles
8

Haq, M. Z., and M. R. Mohiuddin. "Thermodynamic Analysis of a Multi-Fueled Single Cylinder SI Engine." In ASME 2011 International Mechanical Engineering Congress and Exposition. ASMEDC, 2011. http://dx.doi.org/10.1115/imece2011-62423.

Full text
Abstract:
The paper presents a thermodynamic analysis of a single cylinder four-stroke spark-ignition (SI) engine fuelled by four fuels namely iso-octane, methane, methanol and hydrogen. In SI engines, due to phenomena like ignition delay and finite flame speed manifested by the fuels, the heat addition process is not instantaneous, and hence ‘Weibe function’ is used to address the realistic heat release scenario of the engine. Empirical correlations are used to predict the heat loss from the engine cylinder. Physical states and chemical properties of gaseous species present inside the cylinder are determined using first and second law of thermodynamics, chemical kinetics, JANAF thermodynamic data-base and NASA polynomials. The model is implemented in FORTRAN 95 using standard numerical routines and some simulation results are validated against data available in literature. The second law of thermodynamics is applied to estimate the change of exergy i.e. the work potential or quality of the in-cylinder mixture undergoing various phases to complete the cycle. Results indicate that, around 4 to 24% of exergy initially possessed by the in-cylinder mixture is reduced during combustion and about 26 to 42% is left unused and exhausted to the atmosphere.
APA, Harvard, Vancouver, ISO, and other styles
9

Briggs, Maxwell H., Joseph M. Prahl, Robert Bruckner, and Brian Dykas. "High Pressure Performance of Foil Journal Bearings in Various Gases." In STLE/ASME 2008 International Joint Tribology Conference. ASMEDC, 2008. http://dx.doi.org/10.1115/ijtc2008-71274.

Full text
Abstract:
Foil bearings offer several advantages over traditional oil-lubricated bearings in closed Brayton Cycle (CBC) systems, such as those proposed for long-term space power generation. Proposed CBCs require foil bearings to use an inert gas lubricant at pressures as high as 3.0 MPa as the bearing lubricant. The High Pressure Rig (HPR) at the NASA Glenn Research Center is used to measure foil bearing power loss using potential CBC working fluids at and beyond proposed CBC peak pressures. In the current study foil journal bearing power loss is measured in helium, nitrogen, and carbon dioxide from atmospheric pressure to 4.83 MPa and at shaft speeds from 10 krpm to 42 krpm. Bearings operating in helium show no increase in power loss with increasing pressure for the conditions tested. Bearings operating in nitrogen show increases in power loss with increasing pressure at speeds above 19 krpm, while increases in bearing power loss during carbon dioxide testing were seen at 15 krpm. At speeds above these thresholds, power loss is shown to increase more rapidly in carbon dioxide than in nitrogen. Results suggest that bearing power loss performance is dependent on both gas density and shaft speed.
APA, Harvard, Vancouver, ISO, and other styles
10

Garg, Jugal, and Peter McGlaughlin. "Improving Nash Social Welfare Approximations." In Twenty-Eighth International Joint Conference on Artificial Intelligence {IJCAI-19}. California: International Joint Conferences on Artificial Intelligence Organization, 2019. http://dx.doi.org/10.24963/ijcai.2019/42.

Full text
Abstract:
We consider the problem of fairly allocating a set of indivisible goods among n agents. Various fairness notions have been proposed within the rapidly growing field of fair division, but the Nash social welfare (NSW) serves as a focal point. In part, this follows from the 'unreasonable' fairness guarantees provided, in the sense that a max NSW allocation meets multiple other fairness metrics simultaneously, all while satisfying a standard economic concept of efficiency, Pareto optimality. However, existing approximation algorithms fail to satisfy all of the remarkable fairness guarantees offered by a max NSW allocation, instead targeting only the specific NSW objective. We address this issue by presenting a 2 max NSW, Prop-1, 1/(2n) MMS, and Pareto optimal allocation in strongly polynomial time. Our techniques are based on a market interpretation of a fractional max NSW allocation. We present novel definitions of fairness concepts in terms of market prices, and design a new scheme to round a market equilibrium into an integral allocation that provides most of the fairness properties of an integral max NSW allocation.
APA, Harvard, Vancouver, ISO, and other styles
You might also be interested in the extended bibliographies on the topic 'NASA 42' for particular source types:
Journal articles
We offer discounts on all premium plans for authors whose works are included in thematic literature selections. Contact us to get a unique promo code!

To the bibliography