Academic literature on the topic 'LSAC'
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Journal articles on the topic "LSAC"
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Valassi, Elena, Holger Franz, Thierry Brue, Richard A. Feelders, Romana Netea-Maier, Stylianos Tsagarakis, Susan M. Webb, et al. "Diagnostic tests for Cushing's syndrome differ from published guidelines: data from ERCUSYN." European Journal of Endocrinology 176, no. 5 (May 2017): 613–24. http://dx.doi.org/10.1530/eje-16-0967.
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Objective To evaluate which tests are performed to diagnose hypercortisolism in patients included in the European Registry on Cushing’s syndrome (ERCUSYN), and to examine if their use differs from the current guidelines. Patients and methods We analyzed data on the diagnostic tests performed in 1341 patients with Cushing’s syndrome (CS) who have been entered into the ERCUSYN database between January 1, 2000 and January 31, 2016 from 57 centers in 26 European countries. Sixty-seven percent had pituitary-dependent CS (PIT-CS), 24% had adrenal-dependent CS (ADR-CS), 6% had CS from an ectopic source (ECT-CS) and 3% were classified as having CS from other causes (OTH-CS). Results Of the first-line tests, urinary free cortisol (UFC) test was performed in 78% of patients, overnight 1 mg dexamethasone suppression test (DST) in 60% and late-night salivary cortisol (LSaC) in 25%. Use of LSaC increased in the last five years as compared with previous years (P < 0.01). Use of HDDST was slightly more frequent in the last 5 years as compared with previous years (P < 0.05). Of the additional tests, late-night serum cortisol (LSeC) was measured in 62% and 48-h 2 mg/day low-dose dexamethasone suppression test (LDDST) in 33% of cases. ACTH was performed in 78% of patients. LSeC and overnight 1 mg DST supported the diagnosis of both PIT-CS and ADR-CS more frequently than UFC (P < 0.05). Conclusions Use of diagnostic tests for CS varies across Europe and partly differs from the currently available guidelines. It would seem pertinent that a European consensus be established to determine the best diagnostic approach to CS, taking into account specific inter-country differences with regard to the availability of diagnostic tools.
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Nguyen Van, Hung, Nguyet Bui Thi Minh, Linh Bui Thi Thuy, Nghi Nguyen Huu, Tuoi Nguyen Thanh, Tien Nguyen Anh, and Son Le Lam. "Photocatalytic degradation of Rhodamine-B under visible light region by ZnO nanoparticles loaded on activated carbon made from longan seed biomass." Vietnam Journal of Catalysis and Adsorption 9, no. 3 (October 1, 2020): 1–8. http://dx.doi.org/10.51316/jca.2020.041.
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In the present study, the synthesis of ZnO/LSAC through pyrolysis of the carbonized material prepared from longan seed, zinc acetate in alkaline medium. The obtained materials was characterized by means of XRD, SEM, TEM, BET and UV-Vis-DRS. The XRD patterns of ZnO/LSAC nanocomposites were assigned to wurtzite structure of ZnO with crystallite size about 15 to 30 nm. SEM and TEM observations showed the spherical ZnO particles formed on the activated carbon. The band gap energy and specific surface area of ZnO/LSAC were found to be 2.79 eV and 294.4 m2/g, respectively. The photocatalytic activities of the prepared materials were evaluated for the degradation of Rhodamine B (RhB) dye. The removal of RhB was found to be pH dependent, and the optimized removal efficiency reached to 93.75% and the mineralization level was over 84,09% at initial RhB concentration of 40 mg.L-1 andpH 7 following 120 min under visible-light illumination. The kinetic studies showed the decolorizationof RhB followed pseudo first-order kinetics with the rate constant were determined kapp= 1.67Í10-2 min−1
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Liao, Zijun, Karen E. Lamb, David Burgner, Sarath Ranganathan, Jessica E. Miller, Jennifer J. Koplin, Shyamali C. Dharmage, et al. "No obvious impact of caesarean delivery on childhood allergic outcomes: findings from Australian cohorts." Archives of Disease in Childhood 105, no. 7 (January 24, 2020): 664–70. http://dx.doi.org/10.1136/archdischild-2019-317485.
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Background and objectiveAs caesarean delivery and childhood allergy continue to rise, their inter-relationships may change. We examined whether caesarean delivery predicts allergic disease and impaired lung function in two contemporary harmonised population-based cohorts.MethodsParent-reported asthma and eczema data were drawn from two prospective Australian infant cohorts, HealthNuts (n=5276, born 2006–2010) and the Longitudinal Study of Australian Children (LSAC, n=5107, born 2003–2004) at age 6–7 years, and spirometric lung function from LSAC’s Child Health CheckPoint (n=1756) at age 11–12 years. Logistic regression estimated associations between delivery mode and current asthma and eczema at 6–7 years, and linear regression examined lung function at 11–12 years. Models were adjusted for potential confounding factors.ResultsComplete case analysis included 3135 HealthNuts and 3654 LSAC children (32.2% and 30.9% born by caesarean, respectively). An association was evident between caesarean delivery and asthma at age 6–7 years in HealthNuts (adjusted OR (aOR) 1.25, 95% CI 1.00 to 1.57) but not in LSAC (aOR 1.05, 95% CI 0.86 to 1.28), while neither study showed clear associations with eczema (HealthNuts: aOR 1.09, 95% CI 0.88 to 1.35; LSAC: aOR 0.89, 95% CI 0.69 to 1.15). Spirometric lung function parameters at age 11–12 years were similar by delivery mode. Associations were not modified by duration of breast feeding, maternal history of asthma/eczema, childcare attendance, number of older siblings or pet exposure.ConclusionsIn two unselected populations using harmonised protocols, the likely association of caesarean delivery with developing childhood allergy was small.
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Shahunja, K. M., Peter D. Sly, Md Jobayer Chisti, and Abdullah Mamun. "Trajectories of asthma symptom presenting as wheezing and their associations with family environmental factors among children in Australia: evidence from a national birth cohort study." BMJ Open 12, no. 6 (June 2022): e059830. http://dx.doi.org/10.1136/bmjopen-2021-059830.
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ObjectivesAsthma is one of the greatest health burdens, yet contributors to asthma symptom trajectories are understudied in Australian children. We aimed to assess the trajectories of asthma symptom and their associations with several family environmental factors during the childhood period in Australia.DesignSecondary analysis from a cross-sequential cohort study.SettingNationwide representative data from the ‘Longitudinal Study of Australian Children (LSAC)’.ParticipantsParticipants from the LSAC birth cohort.Outcome measuresAsthma symptom trajectory groups.MethodsAsthma symptom presenting as wheezing, family environmental factors and sociodemographic data (2004–2018) were obtained from the LSAC. Group-based trajectory modelling was applied to identify asthma symptom trajectories and multivariable logistic regression models were used to assess the associations between these and environmental factors.ResultsOf 5107 children in the LSAC cohort, 3846 were included in our final analysis. We identified three distinct asthma symptom trajectories from age 0/1 year to 14/15 years: ‘low/no’ (69%), ‘transient high’ (17%) and ‘persistent high’ (14%). Compared with the ‘low/no’ group, children exposed to ‘moderate and declining’ (relative risk ratio (RRR): 2.22, 95% CI 1.94 to 2.54; RRR: 1.26, 95% CI 1.08 to 1.46) and ‘high and persistent’ prevalence of maternal smoking (RRR: 1.41, 95% CI 1.23 to 1.60; RRR: 1.26, 95% CI 1.10 to 1.44) were at increased risk of being classified into the ‘transient high’ and ‘persistent high’ trajectories of asthma symptom. Persistently bad external dwelling conditions (RRR: 1.27, 95% CI 1.07 to 1.51) were associated with ‘transient high’ trajectory while ‘moderate and increasing’ conditions of cluttered homes (RRR: 1.37, 95% CI 1.20 to 1.56) were associated with ‘persistent high’ trajectory of asthma symptom. Exposure to tobacco smoke inside the house also increased the risk of being in the ‘persistent high’ trajectory group (RRR: 1.30, 95% CI 1.12 to 1.50).ConclusionPoor home environment increased the risk of asthma symptom during childhood. Improving home environment and reducing exposure to tobacco smoke may facilitate a favourable asthma symptom trajectory during childhood.
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Shahunja, K. M., Peter D. Sly, Md Jobayer Chisti, and Abdullah Mamun. "Trajectories of asthma symptom presenting as wheezing and their associations with family environmental factors among children in Australia: evidence from a national birth cohort study." BMJ Open 12, no. 6 (June 2022): e059830. http://dx.doi.org/10.1136/bmjopen-2021-059830.
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ObjectivesAsthma is one of the greatest health burdens, yet contributors to asthma symptom trajectories are understudied in Australian children. We aimed to assess the trajectories of asthma symptom and their associations with several family environmental factors during the childhood period in Australia.DesignSecondary analysis from a cross-sequential cohort study.SettingNationwide representative data from the ‘Longitudinal Study of Australian Children (LSAC)’.ParticipantsParticipants from the LSAC birth cohort.Outcome measuresAsthma symptom trajectory groups.MethodsAsthma symptom presenting as wheezing, family environmental factors and sociodemographic data (2004–2018) were obtained from the LSAC. Group-based trajectory modelling was applied to identify asthma symptom trajectories and multivariable logistic regression models were used to assess the associations between these and environmental factors.ResultsOf 5107 children in the LSAC cohort, 3846 were included in our final analysis. We identified three distinct asthma symptom trajectories from age 0/1 year to 14/15 years: ‘low/no’ (69%), ‘transient high’ (17%) and ‘persistent high’ (14%). Compared with the ‘low/no’ group, children exposed to ‘moderate and declining’ (relative risk ratio (RRR): 2.22, 95% CI 1.94 to 2.54; RRR: 1.26, 95% CI 1.08 to 1.46) and ‘high and persistent’ prevalence of maternal smoking (RRR: 1.41, 95% CI 1.23 to 1.60; RRR: 1.26, 95% CI 1.10 to 1.44) were at increased risk of being classified into the ‘transient high’ and ‘persistent high’ trajectories of asthma symptom. Persistently bad external dwelling conditions (RRR: 1.27, 95% CI 1.07 to 1.51) were associated with ‘transient high’ trajectory while ‘moderate and increasing’ conditions of cluttered homes (RRR: 1.37, 95% CI 1.20 to 1.56) were associated with ‘persistent high’ trajectory of asthma symptom. Exposure to tobacco smoke inside the house also increased the risk of being in the ‘persistent high’ trajectory group (RRR: 1.30, 95% CI 1.12 to 1.50).ConclusionPoor home environment increased the risk of asthma symptom during childhood. Improving home environment and reducing exposure to tobacco smoke may facilitate a favourable asthma symptom trajectory during childhood.
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Clifford, Susan A., Sarah Davies, and Melissa Wake. "Child Health CheckPoint: cohort summary and methodology of a physical health and biospecimen module for the Longitudinal Study of Australian Children." BMJ Open 9, Suppl 3 (July 2019): 3–22. http://dx.doi.org/10.1136/bmjopen-2017-020261.
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Objectives‘Growing Up in Australia: The Longitudinal Study of Australian Children’ (LSAC) is Australia's only nationally representative children’s longitudinal study, focusing on social, economic, physical and cultural impacts on health, learning, social and cognitive development. LSAC's first decade collected wide-ranging repeated psychosocial and administrative data; here, we describe the Child Health CheckPoint, LSAC’s dedicated biophysical module.Design, setting and participantsLSAC recruited a cross-sequential sample of 5107 infants aged 0–1 year and a sample of 4983 children aged 4–5 years in 2004, since completing seven biennial visits. CheckPoint was a cross-sectional wave that travelled Australia in 2015–2016 to reach LSAC’s younger cohort at ages 11–12 years between LSAC waves 6 and 7. Parent–child pairs participated in comprehensive assessments at 15 Assessment Centres nationwide or, if unable to attend, a shorter home visit.MeasuresCheckPoint’s intergenerational, multidimensional measures were prioritised to show meaningful variation within normal ranges and capture non-communicable disease (NCD) phenotype precursors. These included anthropometry, physical activity, fitness, time use, vision, hearing, and cardiovascular, respiratory and bone health. Biospecimens included blood, saliva, buccal swabs (also from second parent), urine, hair and toenails. The epidemiology and parent–child concordance of many measures are described in separate papers.Results1874 (54% of eligible) parent–child pairs and 1051 second parents participated. Participants' geographical distribution mirrored the broader Australian population; however, mean socioeconomic position and parental education were higher and fewer reported non-English-speaking or Indigenous backgrounds. Application of survey weights partially mitigates that the achieved sample is less population representative than previous waves of LSAC due to non-random attrition. Completeness was uniformly high for phenotypic data (>92% of eligible), biospecimens (74%–97%) and consent (genetic analyses 98%, accessing neonatal blood spots 97%, sharing 96%).ConclusionsCheckPoint enriches LSAC to study how NCDs develop at the molecular and phenotypic levels before overt disease emerges, and clarify the underlying dimensionality of health in childhood and mid-adulthood.
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Masinter, Michael R. "Best practices report from LSAC settlement offers guidance." Disability Compliance for Higher Education 20, no. 9 (March 17, 2015): 3. http://dx.doi.org/10.1002/dhe.30046.
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Masinter, Michael R. "LSAC settlement offers tips for evaluating testing accommodation requests." Campus Legal Advisor 15, no. 9 (April 17, 2015): 6. http://dx.doi.org/10.1002/cala.30100.
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Ostberg, Karen L., Amanda J. DeRocco, Shreni D. Mistry, Mary Kathryne Dickinson, and Cynthia Nau Cornelissen. "Conserved Regions of Gonococcal TbpB Are Critical for Surface Exposure and Transferrin Iron Utilization." Infection and Immunity 81, no. 9 (July 8, 2013): 3442–50. http://dx.doi.org/10.1128/iai.00280-13.
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ABSTRACTThe transferrin-binding proteins TbpA and TbpB enableNeisseria gonorrhoeaeto obtain iron from human transferrin. The lipoprotein TbpB facilitates, but is not strictly required for, TbpA-mediated iron acquisition. The goal of the current study was to determine the contribution of two conserved regions within TbpB to the function of this protein. Using site-directed mutagenesis, the first mutation we constructed replaced the lipobox (LSAC) of TbpB with a signal I peptidase cleavage site (LAAA), while the second mutation deleted a conserved stretch of glycine residues immediately downstream of the lipobox. We then evaluated the resulting mutants for effects on TbpB expression, surface exposure, and transferrin iron utilization. Western blot analysis and palmitate labeling indicated that the lipobox, but not the glycine-rich motif, is required for lipidation of TbpB and tethering to the outer membrane. TbpB was released into the supernatant by the mutant that produces TbpB LSAC. Neither mutation disrupted the transport of TbpB across the bacterial cell envelope. When these mutant TbpB proteins were produced in a strain expressing a form of TbpA that requires TbpB for iron acquisition, growth on transferrin was either abrogated or dramatically diminished. We conclude that surface tethering of TbpB is required for optimal performance of the transferrin iron acquisition system, while the presence of the polyglycine stretch near the amino terminus of TbpB contributes significantly to transferrin iron transport function. Overall, these results provide important insights into the functional roles of two conserved motifs of TbpB, enhancing our understanding of this critical iron uptake system.
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Van den Eynde, Annelies, and Dimitri Mortelmans. "The Consequences of Work–Family Enrichment in Families on the Behaviour of Children." Social Sciences 9, no. 10 (October 7, 2020): 180. http://dx.doi.org/10.3390/socsci9100180.
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This study considers the spillover effect of work-family enrichment in parents on the behaviour of their children. Using a mediation model with parental well-being and parenting styles, the study unravels the associations between a positive perspective on work-life balance and the outcomes in a child’s live. Using 4012 parents from the data of the Australian LSAC (Growing up in Australia), the model shows that children’s behaviour is influenced by parents’ experience of work-family enrichment through parental well-being. Also, parenting performance functions as a mediator between work-family enrichment and the behaviour of the child. Parents show more stimulating parenting behaviour when they experience enrichment between work and their family.
Dissertations / Theses on the topic "LSAC"
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Williams, Kate Elizabeth. "Self-regulation from birth to age seven : associations with maternal mental health, parenting, and social, emotional and behavioural outcomes for children." Thesis, Queensland University of Technology, 2014. https://eprints.qut.edu.au/71568/1/Kate_Williams_Thesis.pdf.
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Self-regulation refers to our individual capacities to regulate our behaviours, emotions, and thoughts, with these skills developing rapidly across early childhood. This thesis examined sleep, emotional, and cognitive regulation development, and related parental influences, for children participating in the Longitudinal Study of Australian Children. Important longitudinal associations among children's self-regulation, maternal mental health, parenting, and later behaviour problems for children were also investigated. A unique contribution of this research was a prevalence estimate of early childhood self-regulation problems in Australian children that was documented for the first time.
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Hayes, Nicole. "Continuity and change in family engagement in home learning activities across the early years." Thesis, Queensland University of Technology, 2015. https://eprints.qut.edu.au/84653/1/Nicole_Hayes_Thesis.pdf.
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This research utilised data from The Longitudinal Study of Australian Children and explored continuity and change in parental engagement in home learning activities with young children. The findings indicated a decrease over time in parental engagement with children, from age to 2-3 years to 6-7 years. Rate of decrease impacted negatively on learning outcomes for language and literacy, and mathematical thinking, in the early years of school, when children were aged 6-7 years. Shared reading with children and interactions around everyday home activities and play, in which children and parents participate together, impact on children's later development.
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Malheiros, Dorotea Starling. "Estudo descritivo do trauma ortopédico em crianças e adolescentes atendidas em centro de atendimento nível II." Universidade Federal de Minas Gerais, 2009. http://hdl.handle.net/1843/LSPC-8RWH9F.
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Between April 27th 1995 and April 26th 2005, patients with external cause lesions seen at the pediatric orthopedic outpatient clinic of the Maria Amelia Lins Hospital were studied. The objective was to identify the characteristics, patients profile through the variables: age, gender, trauma mechanism, side, topographic localization, associated injuries and compare the epidemiological results with the literature findings. The inclusion criterias were: have a external cause lesion, find the medical records with the appropriate research informations and have open physes. In the above mentioned period 2472 patients were identified, of which 1199 fitted the inclusion criterias. Patients identification and lesion characteristics were taken from the medical records. Age was count in absolute years. Mechanism of trauma were grouped in falls, traffic accidents, direct trauma, others and without information. Thetypes of lesions were divided in amputation, fractures, epiphysiolises, luxations, head trauma, contusions, internal organs injuries, face injuries, and others. Fractures, fracture-luxation, epiphysiolises and luxations were, also, classified as open or closed. Topographic localizationswere classified in relation to bony segments. Patients were grouped in general population, isolated injuries, multiple lesions that had more then one segment and/or of other organs involved. The orthopedic injuries that required more secondary attention were described asprincipal. From the general sample, 838 (68.9%) patients had isolated injuries, 361 (30.1%) patients had 884 multiple lesions. Mean age was 7.6±3.4 years. Masculine gender and the left side predominated. In the isolated injuries the upper limbs were more affected while lowerlimbs were more affected in multiple lesions. The most common trauma mechanisms in general and isolated groups, were falls (39.0% e 44,3%) and traffic accidents in multiple injuries (42,7%). Fracture was the most frequent type of lesion was (73,0% - general sample, 85,3% - isolated injuries and 61,1% - in multiple injuries). Elbow fractures (24%) were the most common topographic localization among the isolated injuries, while leg fractures (12,9%) were the most common among the multiple injuries. One associated injury was seen in 67.% of the multiple lesions 24.3% had two, 5.3% had three and 3.3% had four. Mainly the associationamong elbow fractures and forearm fractures with 25 cases. In conclusion, the descriptive characteristics were the same as the literature. The isolated injury patients´ profile is: boys, inschool age, victims of fall, with upper limb long bone closed fractures. The multiple injury patients´ profile is: boys, at school age, victims of traffic accidents, with lower limb long bone fractures associated with other injuries. Protocols development and introduction are of essential for bias exclusion and comparison in this type of study.No período de 27/04/1995 a 26/04/2005, estudou-se as vítimas de lesões de causa externa atendidas no Ambulatório de Ortopedia Pediátrica do Hospital Maria Amélia Lins. Os objetivos foram identificar as características das lesões ortopédicas; o perfil dos pacientes quanto às variáveis: idade, gênero, mecanismo de trauma, tipo de lesão, lado, localização topográfica e afecções associadas; e comparar os dados epidemiológicos com os da literatura. Foram critérios de inclusão ser vítimas de lesões de causa externa, a localização do prontuário, oregistro nele dos dados necessários à pesquisa, e a presença de fise aberta. No período, foram identificados 2472 pacientes, dos quais 1199 se encaixavam nos critérios de inclusão. Foram extraídos dos prontuários dados de identificação do paciente e dados relativos às lesões observadas. A variável idade foi registrada em números absolutos de anos de vida. Os mecanismos de trauma foram agrupados em acidentes de trânsito; quedas; trauma direto;outros e sem relato. Os tipos de lesões foram subdivididos em amputações; fraturas; epifisiólise; luxações; traumatismo cranioencefálico; contusões; lesões de órgãos internos; lesões de face; e outras lesões. As fraturas, fraturas-luxações, as epifisiólises e luxações foram classificadas, quanto à exposição, em expostas e fechadas. A localização topográfica das lesões foi classificada em relação aos segmentos ósseos nos quais ocorreram. Os pacientes foram agrupados em amostra geral, portadores de lesões isoladas e portadores de lesões múltiplas, considerando-se essas últimas as que acometeram mais de um segmento do esqueleto e/ou lesões de outros órgãos ou sistemas. A lesão musculoesquelética que necessitou mais atenção secundária foi descrita como lesão principal. Da amostra geral, 838 (68,9%) pacientes tiveram lesões isoladas e 361 (30,1%) presentaram 884 lesões. A média de idade foi 7,6±3,4 anos. Houve predomínio do gênero masculino e do lado esquerdo. Os membros superiores preponderaram nas lesões isoladas e os membros inferiores nas lesões múltiplas. O mecanismo de trauma mais comum na amostra geral e no grupo lesões isoladas foi a queda(39,0% e 44,3% respectivamente) e, nas lesões múltiplas, foi o acidente de trânsito (42,7%). O tipo de lesão mais frequente foi a fratura (73,0% - amostra geral, 85,3% - lesões isoladas e 61,1% - nas múltiplas). Quanto à localização topográfica, nas lesões isoladas predominaram asfraturas de cotovelo (24%) e, nas lesões múltiplas, as fraturas dos ossos da perna (12,9%). Nos portadores de lesões múltiplas, 67,1% tinham uma lesão associada, 24,3% duas, 5,3% três, e 3,3% quatro, com destaque para as fraturas de cotovelo com as fraturas de antebraço (25 casos). Concluiu-se que as características descritivas se encontram em conformidade com aliteratura. Os portadores de lesões isoladas podem ser definidos como meninos em idade escolar, vítimas de queda, apresentando fratura fechada de osso longo do membro superior. Os portadores de lesões múltiplas caracterizaram-se por ser meninos, em idade escolar, vítimas de acidente de trânsito apresentando fratura de ossos do membro inferior acompanhada de outra lesão. O desenvolvimento e a implantação de protocolos deatendimento são de fundamental importância para a eliminação de vieses na coleta de dados nesse tipo de estudo.
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Oertel, Robert, Peter Wagner, Jürgen Krimmling, and Matthias Körner. "Verlustzeitenbasierte LSA-Steuerung eines Einzelknotens." Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2012. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-91871.
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Neue Methoden zur Verkehrsdatenerfassung wie die Fahrzeug-Infrastruktur-Kommunikation, der Floating Car-Ansatz und die Videodetektion eröffnen die Möglichkeit, neue Verfahren zur verkehrsabhängigen Lichtsignalanlagensteuerung zu realisieren. In dem Beitrag wird ein Verfahren beschrieben, das aus diesen Quellen Daten in Form von Fahrzeugverlustzeiten direkt zur Steuerung eines Einzelknotens verwendet. Die robuste Ausgestaltung des Verfahrens sorgt dabei dafür, dass auch mit einer lückenhaften Datenlage, wie z. B. aufgrund geringer Ausstattungsraten kommunikationsfähiger Fahrzeuge, angemessen umgegangen werden kann. Mit Hilfe einer mikroskopischen Simulationsstudie wird nachgewiesen, dass das neue Verfahren bei der Qualität des Verkehrsablaufs das gleiche Niveau wie eine traditionelle Zeitlückensteuerung erreicht oder dieses unter bestimmten Bedingungen sogar übersteigt. Mit abnehmender Ausstattungsrate ergibt sich dabei allerdings ein Qualitätsverlust, der ebenfalls mit Hilfe der mikroskopischen Simulation quantifiziert wird und wichtige Erkenntnisse für einen möglichen Praxistest liefertState-of-the-art traffic data sources like Car-to-Infrastructure communication, Floating Car Data and video detection offer great new prospects for vehicle-actuated traffic signal control. Due to this, the article deals with a recent approach which uses vehicles’ delay times for real-time control of traffic signals at an isolated intersection. One of the strengths of the new approach is that it can handle also incomplete data sets, e.g. caused by low penetration rates of vehicles equipped with Car-to-Infrastructure communication technology, in an appropriate manner. Based on a microscopic simulation study the high quality of this innovative approach is demonstrated, which is equal or even outperforms the well-known headway-based control. However, a decreasing penetration rate of equipped vehicles means a reduced quality of signals’ control, which is quantified in the microscopic simulation study, too, and provides useful information for tests in the field
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SANTOS, João Carlos Alves dos. "Avaliação automática de questões discursivas usando LSA." Universidade Federal do Pará, 2016. http://repositorio.ufpa.br/jspui/handle/2011/7485.
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Este trabalho investiga o uso de um modelo usando Latent Semantic Analysis (LSA) na avaliação automática de respostas curtas, com média de 25 a 70 palavras, de questões discursivas. Com o surgimento de ambientes virtuais de aprendizagem, pesquisas sobre correção automática tornaram-se mais relevantes, pois permitem a correção mecânica com baixo custo para questões abertas. Além disso, a correção automática permite um feedback instantâneo e elimina o trabalho de correção manual. Isto possibilita criar turmas virtuais com grande quantidade de alunos (centenas ou milhares). Pesquisas sobre avaliação automática de textos estão sendo desenvolvidas desde a década de 60, mas somente na década atual estão alcançando a acurácia necessária para uso prático em instituições de ensino. Para que os usuários finais tenham confiança, o desafio de pesquisa é desenvolver sistemas de avaliação robustos e com acurácia próxima de avaliadores humanos. Apesar de alguns estudos apontarem nesta direção, existem ainda muitos pontos a serem explorados nas pesquisas. Um ponto é a utilização de bigramas com LSA, mesmo que não contribua muito com a acurácia, contribui com a robustez, que podemos definir como confiabilidade2, pois considera a ordem das palavras dentro do texto. Buscando aperfeiçoar um modelo LSA na direção de melhorar a acurácia e aumentar a robustez trabalhamos em quatro direções: primeira, incluímos bigramas de palavras no modelo LSA; segunda, combinamos modelos de co-ocorrência de unigrama e bigramas com uso de regressão linear múltipla; terceira, acrescentamos uma etapa de ajustes sobre a pontuação do modelo LSA baseados no número de palavras das respostas avaliadas; quarta, realizamos uma análise da distribuição das pontuações atribuídas pelo modelo LSA contra avaliadores humanos. Para avaliar os resultados comparamos a acurácia do sistema contra a acurácia de avaliadores humanos verificando o quanto o sistema se aproxima de um avaliador humano. Utilizamos um modelo LSA com cinco etapas: 1) pré- processamento, 2) ponderação, 3) decomposição a valores singulares, 4) classificação e 5) ajustes do modelo. Para cada etapa explorou-se estratégias alternativas que influenciaram na acurácia final. Nos experimentos obtivemos uma acurácia de 84,94% numa avaliação comparativa contra especialistas humanos, onde a correlação da acurácia entre especialistas humanos foi de 84,93%. No domínio estudado, a tecnologia de avaliação automática teve resultados próximos aos dos avaliadores humanos mostrando que esta alcançando um grau de maturidade para ser utilizada em sistemas de avaliação automática em ambientes virtuais de aprendizagem.
This work investigates the use of a model using Latent Semantic Analysis (LSA) In the automatic evaluation of short answers, with an average of 25 to 70 words, of questions Discursive With the emergence of virtual learning environments, research on Automatic correction have become more relevant as they allow the mechanical correction With low cost for open questions. In addition, automatic Feedback and eliminates manual correction work. This allows you to create classes With large numbers of students (hundreds or thousands). Evaluation research Texts have been developed since the 1960s, but only in the The current decade are achieving the necessary accuracy for practical use in teaching. For end users to have confidence, the research challenge is to develop Evaluation systems that are robust and close to human evaluators. despite Some studies point in this direction, there are still many points to be explored In the surveys. One point is the use of bigrasms with LSA, even if it does not contribute Very much with the accuracy, contributes with the robustness, that we can define as reliability2, Because it considers the order of words within the text. Seeking to perfect an LSA model In the direction of improving accuracy and increasing robustness we work in four directions: First, we include word bigrasms in the LSA model; Second, we combine models Co-occurrence of unigram and bigrams using multiple linear regression; third, We added a stage of adjustments on the LSA model score based on the Number of words of the responses evaluated; Fourth, we performed an analysis of the Of the scores attributed by the LSA model against human evaluators. To evaluate the We compared the accuracy of the system against the accuracy of human evaluators Verifying how close the system is to a human evaluator. We use a LSA model with five steps: 1) pre-processing, 2) weighting, 3) decomposition a Singular values, 4) classification and 5) model adjustments. For each stage it was explored Strategies that influenced the final accuracy. In the experiments we obtained An 84.94% accuracy in a comparative assessment against human Correlation among human specialists was 84.93%. In the field studied, the Evaluation technology had results close to those of the human evaluators Showing that it is reaching a degree of maturity to be used in Assessment in virtual learning environments. Google Tradutor para empresas:Google Toolkit de tradução para appsTradutor de sitesGlobal Market Finder.
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Lähetkangas, K. (Kalle). "Special applications and spectrum sharing with LSA." Doctoral thesis, Oulun yliopisto, 2019. http://urn.fi/urn:isbn:9789526223940.
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Abstract The commercial long-term evolution (LTE) networks of today offer fast and regionally wide access to the Internet and to the commercial applications and services at a reasonable price. At the same time, public safety (PS) users are still communicating with old-fashioned, second-generation voice and data services. Recently, the commercial LTE networks have been standardized to offer capabilities to mission-critical users. However, the commercial networks do not yet fully support the coverage requirements of the PS users. Moreover, the commercial infrastructure might be out of order in critical scenarios where PS actors are needed. Thus, the PS users require, for example, rapidly deployed LTE networks to support their own communication. This thesis studies the PS use of commercial operators' LTE networks and rapidly deployed closed LTE networks. The key tasks are to find out how to connect users seamlessly together between the different networks as well as finding out how the frequency planning is implemented. This thesis provides practical design solutions to guarantee network interoperability by connecting the networks as well as radio spectrum utilization solutions by licensed shared access (LSA). While the concept of LSA has been well developed, it has not been thoroughly investigated from the point of view of the PS actors, who have special requirements and should benefit from the concept. Herein, the alternatives for spectrum sharing between PS and commercial systems are discussed. Moreover, the thesis develops a specific LSA spectrum sharing system for the PS actors deploying their own network in scenarios where the commercial networks are insufficient. The solution is a robust LSA-based spectrum sharing mechanism. Note that PS actors also need to be able to utilize the spectrum when the LSA system is not available and when the commercial system has failed. Thus, this thesis proceeds on developing sensing methods for complementing LSA, where the sensing methods guarantee spectrum information for a rapidly deployed PS network. It is shown how PS actors can utilize available spectrum with a secondary spectrum licence. This is a good alternative to reserving the spectrum completely. The work assembles missing pieces of existing methods to ensure the functionality of the commercial and of the supporting rapidly deployed networks, both in terms of spectrum usage and application servicesTiivistelmä Kaupalliset long-term evolution (LTE) -verkot tarjoavat nopean, edullisen ja alueellisesti kattavan pääsyn Internettiin sekä laajaan valikoimaan sovelluksia. Samaan aikaan turvallisuustoimijat (public safety (PS) -toimijat) käyttävät vanhanaikaisia äänen sekä vaatimattoman datayhteyden tarjoavia verkkoja. LTE-verkot ovat kuitenkin äskettäin standardoitu tarjoamaan valmiudet myös toimintokriittiseen kommunikointiin. Toisaalta, kaupalliset LTE-verkot eivät vielä tarjoa esimerkiksi tarvittavaa alueellista kattavuutta PS-käyttäjille. Lisäksi, kaupalliset verkot saattavat olla epäkunnossa kriittisissä tilanteissa. Tämän vuoksi PS-toimijat tarvitsevat omia nopeasti pystytettäviä LTE-verkkoja tukemaan nykyaikaista viestintäänsä. Opinnäytetyössä tutkitaan näiden nopeasti pystytettävien LTE-verkkojen käyttöä kaupallisten LTE-verkkojen kanssa. Keskeiset tehtävät ovat eri verkkojen PS-toimijoiden saumaton yhdistäminen sekä verkkojen taajuusjaon toteuttaminen. Tämä opinnäytetyö tarjoaa käytännön ratkaisuja verkkojen yhteentoimivuuden takaamiseksi ja radiotaajuuksien jakoratkaisuja lisensoidun jaetun käyttöoikeuden licensed shared access (LSA) -metodin avulla. Vaikka LSA:n käsite on jo pitkälle kehitetty, sitä ei ole tutkittu perusteellisesti PS-toimijoiden näkökulmasta ottaen huomioon heidän erityisvaatimuksensa. Tässä työssä syvennytään näiltä osin LSA järjestelmään yhtenä vaihtoehtona taajuuksien saamiseksi nopeasti pystytettäville verkoille. Lisäksi työssä kehitetään robusti LSA-pohjainen taajuuksien jakamisjärjestelmä nopeasti pystytettäville verkoille tilanteissa, joissa kaupalliset verkot ovat riittämättömät. Huomaa, että PS-toimijoiden on pystyttävä hyödyntämään taajuuksia myös silloin, kun LSA-järjestelmän kaikki osat eivät ole käytettävissä ja kun kaupallinen LTE järjestelmä on alhaalla. Tätä varten opinnäytetyössä kehitetään LSA:ta täydentävä havainnointimenetelmä, jolla taataan taajuustiedot vapaista taajuuksista nopeasti pystytettäville verkoille, sekä näytetään, miten PS-toimijat voivat hyödyntää LSA:ta toissijaisen taajuuslisenssin avulla. Tämä on hyvä vaihtoehto radiospektrin varaamiseksi kokonaan. Työ kokoaa puuttuvia osia olemassa oleviin menetelmiin, jotta voidaan varmistaa kaupallisten verkkojen toimivuus PS-käyttäjille yhdessä niitä tukevien nopeasti pystytettävien verkkojen kanssa taajuuksien käytön ja sovelluspalvelujen osalta
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Madola, Ondrej. "NÁVRH KŘÍDLA PRO LETOUN KATEGORIE CS LSA." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2014. http://www.nusl.cz/ntk/nusl-231206.
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The aim of the thesis is design and technological design of wing with significant reduction manual work and number of preparations in preparing part of structures. The first part of the work is to explanation the issues and machining metal parts forming wings and also the use of CAD systems. The next section describes several design proposals wings, strength test and compare price and weight of main girders with breams made of L-profiles. Followed by the technological process of production individual part design and control hems of sheet metal part design. The conclusion is dedicated to building assembler wings.
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Zorzi, Giorgia. "Coordination and gapping in Catalan Sign Language (LSC)." Doctoral thesis, Universitat Pompeu Fabra, 2018. http://hdl.handle.net/10803/665045.
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This thesis gives a description and a syntactic analysis for coordination and gapping in conjunction in Catalan Sign Language (LSC) within the framework of Generative Grammar and Minimalism. Regarding coordination, Coordination Phrase (CoP) is proposed as the category for conjunctive, disjunctive and adversative coordination, assuming that the conjuncts are specifiers and complements of CoP in a right-branching coordination structure. The specific derivation for each types of coordination is then applied.
As for gapping in conjunction, in LSC it shows similarities with VP-ellipsis, especially because it can appear also in subordination. Moreover, the availability of only distributed scope negation (¬A&¬B) and the presence of contrastive topic and contrastive focus require a large coordination structure, that is, CP coordination. In order to derive gapping, I propose movement of the arguments to TopP and FocP followed by the deletion of TP at PF, with [E] feature in the head of FocP.Aquesta tesi ofereix una descripció i una anàlisi sintàctica per a la coordinació i el “gapping” en coordinació conjuntiva en llengua de signes catalana (LSC), dins el marc generativista i minimista. Pel que fa a la coordinació, la categoria sintàctica que es proposa és “Coordination Phrase” (CoP) per a la coordinació conjuntiva, disjuntiva i adversativa. A l’estructura, ramificada a la dreta, els constituents de la conjunció són especificadors i complements de CoP. La derivació per a cada tipus de coordinació s’aplica a partir d’aquest model. Pel que fa al “gapping”, mostra proprietats similars a l’el·lipsi de SV (VP-ellipsis), sobretot perquè pot aparèixer en subordinació. A més, la l’existència només d’un abast distribuït de la negació (¬A&¬B) i la presència de tòpic i focus contrastius mostra la necessitat de tenir una coordinació “àmplia” on els dos conjunts siguin CPs. En la derivació de “gapping”, els arguments es mouen a TopP i FocP, seguits de l’eliminació del TP a PF, ambel tret [E] posicionat al nucli de FocP.
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Denhard, August. "Lute realizations for the English cavalier songs (1630-1670) : a guide for performers /." Online version, 2006. http://www.cs.dartmouth.edu/~lsa/associated/Denhard/index.html.
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Mosella, Sanz Marta. "Les construccions relatives en llengua de signes catalana (LSC)." Doctoral thesis, Universitat de Barcelona, 2012. http://hdl.handle.net/10803/123717.
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Aquesta tesi presenta la primera descripció de les construccions relatives (CR) restrictives en llengua de signes catalana (LSC). A més, inclou una proposta d’anàlisi en el marc de la gramàtica generativa transformacional informada tipològicament.
Respecte a la tipologia sintàctica de les CR, aportem proves que mostren que aquestes construccions, en LSC, són estructures circumnominals, és a dir, amb el pivot (o antecedent) dins de l’oració relativa (OR). Això contrasta amb les CR més comunes a les llengües indoeuropees, les adnominals, en què el pivot apareix fora de l’OR. Les CR circumnominals de la LSC, d’acord amb el que diu la tipologia, presenten un determinant que nominalitza l’estructura.
Les CR circumnominals de la LSC no apareixen mai a la seva posició bàsica dins de l’oració matriu sinó que han d’aparèixer o bé avantposades o bé posposades. Aquesta mateixa distribució s’observa a les CR circumnominals d’altres llengües de signes, com ara la llengua de signes italiana (LIS).
L’anàlisi que presentem és essencialment la d’elevació, en la línia de Kayne (1994), encara que hi introduïm algunes modificacions per tal de donar compte de les dades de la LSC. Aquesta anàlisi, en principi, seria d’aplicació a les CR circumnominals en general, es tracti de llengües orals o signades.
Aquest treball representa, doncs, una contribució tant a la tipologia com a la lingüística teòrica.This work contains the first description of Catalan Sign Language (LSC) Relative Clauses (RCs). Also, it proposes an analysis within the Generative framework that takes a typological approach. Regarding the syntactic typology of LSC RCs, they are circumnominal. In other words, they show the pivot (or antecedent) inside the RC. This contrasts with the most common RCs in Indo-European languages, the adnominal ones, in which the pivot appears outside the RC, that is, in the matrix clause. Other evidence that supports the idea that RCs in LSC are circumnominal is put forward. For instance, this structure shows a determiner that nominalizes the whole construction, as usually found in circumnominal RCs across languages. Circumnominal RCs in LSC never appear in its basic position inside the matrix clause. They have to appear or fronted or postposed to the matrix one. This same distribution is also found in other sign language RCs, for instance, in Italian Sign Language (LIS). The analysis presented here essentially follows the raising one (Kayne 1994). However, I have added some modifications in order to take into account crucial LSC data. The resulting analysis can be applied to the circumnominal construction as a whole, that is, in both oral and signed languages. To sum up, this work is a contribution to both typology and theoretical linguistics.
Books on the topic "LSAC"
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Wightman, Linda F. LSAC national longitudinal bar passage study. Newtown, PA: Law School Admission Council, 1998.
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Ramsey, Henry. LSAC national longitudinal bar passage study. Newtown, PA: The Council, c1998., 1998.
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Association, American Bar. ABA-LSAC official guide to ABA-approved law schools. 2nd ed. Newtown, PA: Law School Admission Council, American Bar Association, 2009.
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Association, American Bar. ABA-LSAC official guide to ABA-approved law schools. 2nd ed. Newtown, Pa: Law School Admission Council, American Bar Association, 2010.
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Long, Tùng. Muot lsan lsam lzo. TP. HCM [i.e. Thành phro Hso Chí Minh]: NXB Văn nghue, 2008.
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Trung, Sĩ. Muot lsan lsam lzo: Truyuen. Paris: Nam Á, 1986.
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Chambers, David L. Debts, job choices, and financial burden: Educational debts at nine American law schools : a study prepared for the Joint AALS-ABA-LSAC Task Force on Student Financial Aid. [Washington, D.C.?: American Association of Law Schools?, 1991.
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1962-, Rimal Rajiv N., and Orton Peter Z, eds. LSAT. 5th ed. New York: Wiley Pub., 2001.
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Goodman, Eric. LSAT 180. New York, NY: Simon & Schuster, 2001.
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White, Thomas O. LSAT success. Princeton, N.J: Peterson's, 1996.
Find full textBook chapters on the topic "LSAC"
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Leung, Alexander K. C., William Lane M. Robson, Carsten Büning, Johann Ockenga, Janine Büttner, Hartmut Schmidt, Antonio V. Delgado-Escueta, et al. "LSA/LSEA." In Encyclopedia of Molecular Mechanisms of Disease, 1213. Berlin, Heidelberg: Springer Berlin Heidelberg, 2009. http://dx.doi.org/10.1007/978-3-540-29676-8_5085.
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Lee, Dong Ik, Sadatoshi Kumagai, and Shinzo Kodama. "Reachability of LSFC Nets." In Realization and Modelling in System Theory, 529–39. Boston, MA: Birkhäuser Boston, 1990. http://dx.doi.org/10.1007/978-1-4612-3462-3_59.
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Rodrigues, Bruno, Eduardo Cruz, André Dias, and Manuel F. Silva. "LSA Portraiture Robot." In Advances in Intelligent Systems and Computing, 341–52. Cham: Springer International Publishing, 2015. http://dx.doi.org/10.1007/978-3-319-27149-1_27.
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Lv, Miao-Miao, Si-Bao Chen, and Bin Luo. "LSAM: Local Spatial Attention Module." In Pattern Recognition and Computer Vision, 407–18. Cham: Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-030-60636-7_34.
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Shin, Seung-won, Ki-young Kim, and Jong-soo Jang. "LSAD: Lightweight SYN Flooding Attack Detector." In Distributed Computing and Internet Technology, 385–90. Berlin, Heidelberg: Springer Berlin Heidelberg, 2004. http://dx.doi.org/10.1007/978-3-540-30555-2_45.
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Alizadehasl, Azin, and Maryam Moradian. "Persistent Left Superior Vena Cava (LSVC)." In Atlas of Echocardiography in Pediatrics and Congenital Heart Diseases, 43–45. Berlin, Heidelberg: Springer Berlin Heidelberg, 2021. http://dx.doi.org/10.1007/978-3-662-62341-1_14.
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Kugler, Hillel, Cory Plock, and Amir Pnueli. "Controller Synthesis from LSC Requirements." In Fundamental Approaches to Software Engineering, 79–93. Berlin, Heidelberg: Springer Berlin Heidelberg, 2009. http://dx.doi.org/10.1007/978-3-642-00593-0_6.
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Debije, Michael. "The Luminescent Solar Concentrator (LSC)." In Photovoltaic Solar Energy, 420–30. Chichester, UK: John Wiley & Sons, Ltd, 2017. http://dx.doi.org/10.1002/9781118927496.ch38.
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Blain, A. W. "The LSA and Galaxy Surveys." In ESO Astrophysics Symposia, 70–73. Berlin, Heidelberg: Springer Berlin Heidelberg, 1996. http://dx.doi.org/10.1007/978-3-540-69999-6_7.
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Blain, A. W. "The LSA and Gravitational Lensing." In ESO Astrophysics Symposia, 74–77. Berlin, Heidelberg: Springer Berlin Heidelberg, 1996. http://dx.doi.org/10.1007/978-3-540-69999-6_8.
Full textConference papers on the topic "LSAC"
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Tan, David, Yuanchao Li, Ian Wilkes, Rinaldo L. Miorini, and Joseph Katz. "PIV Measurements of the Flow in the Tip Region of a Compressor Rotor." In ASME 2014 4th Joint US-European Fluids Engineering Division Summer Meeting collocated with the ASME 2014 12th International Conference on Nanochannels, Microchannels, and Minichannels. American Society of Mechanical Engineers, 2014. http://dx.doi.org/10.1115/fedsm2014-21593.
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An axial turbomachine, adapted from the NASA Glenn Low-Speed Axial Compressor (LSAC), has been assembled for detailed flow and turbulence measurements in the JHU optical refractive index matched facility. The test section consists of a row of twenty inlet guide vanes (IGV), followed by fifteen rotor blades, then twenty stator blades. The blades have the same geometry, but lower aspect ratio as the inlet guide vanes and the first stage of the LSAC facility at NASA Glenn. Although smaller in scale, the Reynolds number based on the tip speed and rotor blade chordlength are comparable to those of the LSAC. The casing, rotor blades, as well as half the IGVs and stator blades are made of transparent acrylic, matched with the refractive index of the working fluid, a concentrated solution of sodium iodide and water. The facility is designed to allow optical flow measurements in all three blade rows and from all directions. Results presented in this paper are based on 2D PIV measurements focusing on the flow structure in the tip region of the rotor blade for two flow rates, one of them just above the stall level. Included are phase-averaged distributions of velocity, circumferential vorticity, and turbulent kinetic energy in several meridional planes dissecting the tip at different chordwise locations. They follow the evolution of the Tip Leakage Vortex (TLV) as it rolls up near the blade suction side, migrates across the rotor passage, and subsequently bursts. Upon bursting, the distinct high vorticity core is replaced by a broad region of elevated vorticity, which occupy a substantial fraction of the passage. Sample instantaneous realizations and higher resolution stereo-PIV data are also provided. The turbulent kinetic energy is high near the vortex core, in the shear layer connecting the vortex to the blade tip, and around the point of flow separation on the endwall casing, where the leakage flow meets the main passage flow.
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Tan, David, Yuanchao Li, Ian Wilkes, Rinaldo L. Miorini, and Joseph Katz. "Visualization and Time Resolved PIV Measurements of the Flow in the Tip Region of a Subsonic Compressor Rotor." In ASME Turbo Expo 2014: Turbine Technical Conference and Exposition. American Society of Mechanical Engineers, 2014. http://dx.doi.org/10.1115/gt2014-27195.
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A new optically index matched facility has been constructed to investigate tip flows in compressor-like settings. The blades of the one and a half stage have the same geometry, but lower aspect ratio as the inlet guide vanes and the first stage of the LSAC facility at NASA Glenn. With transparent blades and casings, the new setup enables unobstructed velocity measurements at any point within the tip region, and is designed to facilitate direct measurements of effects of casing treatments on the flow structure. We start with a smooth endwall casing. High speed movies of cavitation and time-resolved PIV measurements have been used to characterize the location, trajectory, and behavior of the Tip Leakage Vortex (TLV) for two flow rates, the lower one representing pre-stall conditions. Results of both methods show consistent trends. As the flow rate is reduced, TLV rollup occurs further upstream, and its initial orientation becomes more circumferential. At pre-stall conditions, the TLV is initially aligned slightly upstream of the rotor passage, and subsequently forced downstream. Within the passage, the TLV breaks up into a large number of vortex fragments, which occupy a broad area. Consequently, the cavitation in the TLV core disappears. With decreasing flow rate, this phenomenon becomes more abrupt, occurs further upstream, and the fragments occupy a larger area.
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Lepicovsky, J., and E. P. Braunscheidel. "Measurement of Flow Pattern Within a Rotating Stall Cell in an Axial Compressor." In ASME Turbo Expo 2006: Power for Land, Sea, and Air. ASMEDC, 2006. http://dx.doi.org/10.1115/gt2006-91209.
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Effective active control of rotating stall in axial compressors requires detailed understanding of flow instabilities associated with this compressor regime. Newly designed miniature high frequency response total and static pressure probes as well as commercial thermoanemometric probes are suitable tools for this task. However, during the rotating stall cycle the probes are subjected to flow direction changes that are far larger than the range of probe incidence acceptance, and therefore probe data without a proper correction would misrepresent unsteady variations of flow parameters. A methodology, based on ensemble averaging, is proposed to circumvent this problem. In this approach the ensemble averaged signals acquired for various probe setting angles are segmented, and only the sections for probe setting angles close to the actual flow angle are used for signal recombination. The methodology was verified by excellent agreement between velocity distributions obtained from pressure probe data, and data measured with thermoanemometric probes. Vector plots of unsteady flow behavior during the rotating stall regime indicate reversed flow within the rotating stall cell that spreads over to adjacent rotor blade channels. Results of this study confirmed that the NASA Low Speed Axial Compressor (LSAC) while in a rotating stall regime at rotor design speed exhibits one stall cell that rotates at a speed equal to 50.6% of the rotor shaft speed.
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Chen, Huang, Yuanchao Li, David Tan, and Joseph Katz. "Visualizations of Flow Structures in the Rotor Passage of an Axial Compressor at the Onset of Stall." In ASME Turbo Expo 2016: Turbomachinery Technical Conference and Exposition. American Society of Mechanical Engineers, 2016. http://dx.doi.org/10.1115/gt2016-57054.
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Flow visualizations and stereoscopic PIV (SPIV) measurements are carried out to study the flow phenomena developing in the rotor passage of an axial compressor at the onset of stall. Experiments have been performed in the JHU optically index-matched facility, using acrylic blades and liquid that have the same optical refractive index. The blade geometries are based on the first one and a half stages of the Low Speed Axial Compressor (LSAC) facility at NASA Glenn. The SPIV measurements provide detailed snapshots and ensemble statistics on the flow in a series of meridional planes. Data recorded in closely spaced planes enable us to obtain ensemble averaged 3D vorticity distributions. High speed imaging of cavitation, performed at low pressure, is used to qualitatively visualize the vortical structures within the rotor passage. The observations are performed just above and at stall conditions. At pre-stall condition, shortly after it rolled up, the tip leakage vortex (TLV) breaks up into widely distributed intermittent vortical structures. In particular, interaction of the backward tip leakage flow with the nearly opposite direction main passage flow under (radially inward) it results in periodic generation of large scale vortices that extend upstream, from the suction side (SS) of one blade to the pressure side (PS) or even near the leading edge of the next blade. When these structures penetrate to the next passage, they trigger formation of a similar phenomenon there, initiating a process that sustains itself. Once they form, these vortices rotate with the blade, indicating little through flow in the tip region. The 3D velocity and vorticity distributions confirm the presence of these large flow structures at the transition between the high circumferential velocity region below the TLV center and the main flow deeper in the passage. Further reduction in flow rate into the stall range caused a rapid increase in the number and scale of these vortices, demonstrating that their formation and proliferation plays a key role in the onset of stall.
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Li, Yuanchao, David Tan, Huang Chen, and Joseph Katz. "Effects of Tip Gap Size on the Flow Structure in the Tip Region of an Axial Turbomachine." In ASME/JSME/KSME 2015 Joint Fluids Engineering Conference. American Society of Mechanical Engineers, 2015. http://dx.doi.org/10.1115/ajkfluids2015-33787.
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This experimental study examines the effect of tip gap size on the flow structure and turbulence in the tip region of an axial turbomachine. The experiments have been performed in the Johns Hopkins University (JHU) optically index-matched facility using an axial compressor settings designed based on the geometry of the inlet guide vanes (IGV) and the first stage of the Low Speed Axial Compressor (LSAC) facility at NASA Glenn. Two sets of rotor blades with similar cross sections, but with tip gap sizes of 0.49% and 2.3% of the blade chord (or 1.1% and 5.4% of the blade span) have been installed and tested. The measurements include performance tests, visualization of the tip leakage vortex (TLV) using cavitation, and stereo PIV (SPIV) measurements in several meridional planes. Increasing the tip gap size causes a substantial reduction in pressure rise across the machine for the same flow rate. The cavitation images, whose trends agree with the velocity and vorticity distributions obtained by the SPIV measurements, show that TLV rollup in the less loaded blade occurs at later chordwise location, and that the vortex remains located closer to the suction side (SS) corner of the originating blade. The delayed detachment from the blade with increasing gap is attributed to the increase of distance of the ‘image vortex’ (wall interaction) from the TLV. The wider gap also reduces the entrainment by the TLV of the endwall boundary layer after it separates at the point where the backward leakage flow meets the main passage flow. The previously observed TLV breakup, which is evident for the narrow gap in the aft part of the rotor passage, is delayed significantly for the wider gap. Consistent changes also appear in the distributions of turbulent kinetic energy, which peaks in the vicinity of the TLV core, the endwall boundary layer separation, and in the shear layer connecting the TLV center to the SS corner of the blade tip.
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Li, Yuanchao, Huang Chen, David Tan, and Joseph Katz. "Effects of Tip Clearance and Operating Conditions on the Flow Structure and Turbulence Within an Axial Compressor Rotor Passage." In ASME Turbo Expo 2016: Turbomachinery Technical Conference and Exposition. American Society of Mechanical Engineers, 2016. http://dx.doi.org/10.1115/gt2016-57050.
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The flows in the tip regions of two rotors with blades of similar geometry but different tip clearance are studied experimentally to determine the effect of gap on the flow structure at different operating conditions. The experiments have been performed in the JHU optically index-matched facility, where the refractive index of the fluid is matched with that of the acrylic rotor blades and casing, facilitating unobstructed Stereo Particle Image Velocimetry (SPIV) measurements. The blade geometries are based on the first one and a half stages of the Low Speed Axial Compressor (LSAC) facility at NASA Glenn. The tip gap sizes are 0.49% and 2.3% of the blade chordlength, and measurements are performed for two flow rates, the lower of which is just above stall conditions. The presence and trajectories of the tip leakage vortex (TLV) and secondary structures are visualized by recording high speed movies of cavitation at lower pressures. The results consist of performance curves, distributions of velocity, circumferential vorticity and turbulent kinetic energy, as well as the strength and trajectory of vortices. Increasing the tip gap reduces the static-to-static pressure coefficient for all flow conditions. For the higher flow rate, a wider tip gap has several effects: (i) It delays the rollup of the TLV and its detachment from the suction side (SS) corner of the blade, presumably due to the larger distance from the endwall casing and the ‘image vortex’. (ii) It alters the blade loading and reduces the circulation shed from the blade. (iii) It delays the onset of TLV bursting in the aft part of the rotor passage. (iv) For both gaps, the endwall boundary layer separates at the point where the leakage flow meets the opposite-direction main passage flow. For the wide gap, the separated layer with opposite sign vorticity remains above the TLV; while for the narrow gap, the TLV entrains this layer around itself. And (v) consistent with the major differences in flow structure, the spatial distributions and magnitudes of all the turbulence intensity are also very different. Trends and flow structure are quite different at pre-stall conditions. Most notably, TLV rollup is still delayed for the wide gap, but vortex bursting and associated arrival of multiple secondary structures to the pressure side (PS) of the next blade occur earlier. Consequently, the turbulence level on both sides of the blade tip is substantially higher, and remnants of the previous TLV are ingested into the next tip gap.
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Chang, Horng-Yi, and Yao-Ming Wang. "Low-Temperature Prepared Multi-Elements Doped CeO2 Electrolyte." In ASME 2009 7th International Conference on Fuel Cell Science, Engineering and Technology. ASMEDC, 2009. http://dx.doi.org/10.1115/fuelcell2009-85221.
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CeO2 materials doped with the di- or tri-valent metals possess high oxide ionic conductivity at low temperature for potential electrolyte use in intermediate temperature solid oxide fuel cell (SOFC). However, multi-elements doped CeO2-based electrolyte, (La1-x-ySrxBay)0.175Ce0.825O2-δ (LSBC) in this work, with pure phase is difficultly synthesized at low calcination temperature. High sintering temperature, e.g. > 1500°C, is also needed in conventional mixed oxide method. In this work, nanoparticles less than 50nm of LSBC can be prepared by solution-evaporation method at constant temperature. Pure fluorite crystal structure can be obtained lower than 700°C. The optimal mole ratio of LSBC/citric acid in prepared solution is 1/2 to achieve homogeneous composition and pure phase of LSBC. Small grain size of about 1μm average is observed for 1300°C-microwave sintered LSBC by solution-evaporation method. The ionic conductivity of 1400°C-conventional sintered and 1300°C-microwave sintered LSBC prepared by solution-evaporation method is about 0.006 S/cm at 600°C but less than 0.004 S/cm at 600°C even for 1500°C-conventional sintered LSBC prepared by mixed oxide method.
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Boos, George, Vladimir Budak, Tatyana Meshkova, and Victor Zheltov. "Lighting Quality Criteria Based on the Luminance Spatial-Angular Distribution." In 31th International Conference on Computer Graphics and Vision. Keldysh Institute of Applied Mathematics, 2021. http://dx.doi.org/10.20948/graphicon-2021-3027-837-845.
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The article is devoted to assessing lighting quality based on lighting engineering design's spatial-angular brightness distribution (LSAD). The main problems of modern lighting design related to the modeling of scenes based on the emissivity equation and restrictions on the use, in this regard, as the main criterion for the lighting quality of Unified Glare Rating (UGR), are considered. The mathematical foundations of the use of LSAD in the practice of lighting engineering design are proposed. The integral equation LSAD is obtained, which allows modeling the brightness at an arbitrary point of the scene volume. A method for solving the formulated equation based on double local estimates of the Monte Carlo method is proposed. The formulated algorithm for calculating LSAD is view-independent: LSAD visualizes the lighting scene at all fixed points. Methods for storing the calculated LSAD are proposed. Based on the LSAD, a new criterion for lighting quality is formulated, which was experimentally tested in a full-scale experiment to evaluate the lighting of Moscow Metro stations. In the experiment, the proposed criterion and UGR were compared. One calculated the quality criteria by the station's photos, and their correlation with observers' assessment was found. Computer models of stations were created, in which quality criteria were also calculated from the experiment viewpoints – obtained good correspondence of the calculations with the estimates of observers.
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Zotov, N., A. Hospach, G. Mauer, D. Sebold, and R. Vaßen. "Deposition of La-Sr-Fe-Co Perovskite Coatings with Different Microstructures by Low Pressure Plasma Spraying." In ITSC2011, edited by B. R. Marple, A. Agarwal, M. M. Hyland, Y. C. Lau, C. J. Li, R. S. Lima, and A. McDonald. DVS Media GmbH, 2011. http://dx.doi.org/10.31399/asm.cp.itsc2011p0640.
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Abstract Preparation of La1-xSrxFe1-yCoyO3-δ (LSFC) coatings by plasma spraying at low pressure (200 Pa) using different plasma spray parameters is reported and discussed. Deposition with Ar-He plasma leads always to formation of coatings containing a mixture of LSFC perovskite, SrLaFeO4, FeCo and metal oxides. Coatings deposited at higher oxygen partial pressures by addition of oxygen into the vacuum chamber contain more than 85% perovskite and only few percent Fe3O4 and/or CoO. The microstructures of the investigated LSFC coatings depend sensitively on the oxygen partial pressure, the substrate temperature and the deposition rate.
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Conlon, William M., Milton J. Venetos, and Scott Hume. "Liquid Salt Combined Cycle." In ASME Turbo Expo 2022: Turbomachinery Technical Conference and Exposition. American Society of Mechanical Engineers, 2022. http://dx.doi.org/10.1115/gt2022-82343.
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Abstract The Liquid Salt Combined Cycle™ (LSCC) is introduced as a hybrid energy storage system that integrates electrically heated thermal energy storage with gas turbine exhaust heat. The objective is to provide low-cost, large-scale storage of increasingly curtailed renewable energy, and to use the stored energy to reduce the fuel heat rate of the combined cycle and the time required from startup to full power. The performance, capital, and operating characteristics of a hybrid storage system using two energy sources are contrasted with thermal generation using a fuel source and with energy storage using an electric source. These characteristics are mapped onto LSCC technology, which is depicted with a diagram showing the flow of electricity into storage during charging, the flow of stored thermal energy during discharge. Stored energy provides latent heating of steam and fuel energy drives a gas turbine whose exhaust gas provides sensible heating of feedwater and superheated steam. A description of the major LSCC equipment is provided: turbomachinery, two-tank molten salt storage, charge heaters, steam generator, exhaust heat recovery, and condensate heating. Material selection and thermal design of LSCC are summarized and performance is compared to simple and combined cycle. The Cost of Energy and Avoided Cost of Energy are assessed for a hypothetical LSCC unit within the ERCOT region.
Reports on the topic "LSAC"
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Rogers, Jessa, Kate E. Williams, Kristin R. Laurens, Donna Berthelsen, Emma Carpendale, Laura Bentley, and Elizabeth Briant. Footprints in Time: Longitudinal Study of Indigenous Children. Queensland University of Technology, October 2022. http://dx.doi.org/10.5204/rep.eprints.235509.
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The Longitudinal Study of Indigenous Children (LSIC; also called Footprints in Time) is the only longitudinal study of developmental outcomes for Aboriginal and Torres Strait Islander children globally. Footprints in Time follows the development of Australian Aboriginal and Torres Strait Islander children to understand what Indigenous children need to grow up strong. LSIC involves annual waves of data collection (commenced in 2008) and follows approximately 1,700 Aboriginal and Torres Strait Islander children living in urban, regional, and remote locations. This LSIC Primary School report has been produced following the release of the twelfth wave of data collection, with the majority of LSIC children having completed primary school (Preparatory [aged ~5 years] to Year 6 [aged ~12 years]). Primary schools play a central role in supporting student learning, wellbeing, and connectedness, and the Footprints in Time study provides a platform for centring Indigenous voices, connecting stories, and exploring emerging themes related to the experience of Indigenous children and families in the Australian education system. This report uses a mixed-methods approach, analysing both quantitative and qualitative data shared by LSIC participants, to explore primary school experiences from the perspective of children, parents and teachers. Analyses are framed using a strengths-based approach and are underpinned by the understanding that all aspects of life are related. The report documents a range of topics including teacher cultural competence, racism, school-based Aboriginal and Torres Strait Islander education activities, parental involvement, engagement, attendance, and academic achievement.
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Duclos, Ronald, and Ned Shepherd. Structured Analysis/Design LSA for the Logistic Support Analysis (LSA) Tasks, LSA Subtask 402.2.2, Sources of Manpower and Personnel Skills. Fort Belvoir, VA: Defense Technical Information Center, October 1990. http://dx.doi.org/10.21236/ada254895.
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Zelenskyi, Arkadii A. Relevance of research of programs for semantic analysis of texts and review of methods of their realization. [б. в.], December 2018. http://dx.doi.org/10.31812/123456789/2884.
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One of the main tasks of applied linguistics is the solution of the problem of high-quality automated processing of natural language. The most popular methods for processing natural-language text responses for the purpose of extraction and representation of semantics should be systems that are based on the efficient combination of linguistic analysis technologies and analysis methods. Among the existing methods for analyzing text data, a valid method is used by the method using a vector model. Another effective and relevant means of extracting semantics from the text and its representation is the method of latent semantic analysis (LSA). The LSA method was tested and confirmed its effectiveness in such areas of processing the native language as modeling the conceptual knowledge of the person; information search, the implementation of which LSA shows much better results than conventional vector methods.
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Coltun, R. The OSPF Opaque LSA Option. RFC Editor, July 1998. http://dx.doi.org/10.17487/rfc2370.
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Berger, L., I. Bryskin, A. Zinin, and R. Coltun. The OSPF Opaque LSA Option. RFC Editor, July 2008. http://dx.doi.org/10.17487/rfc5250.
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Lindem, A., A. Roy, D. Goethals, V. Reddy Vallem, and F. Baker. OSPFv3 Link State Advertisement (LSA) Extensibility. RFC Editor, April 2018. http://dx.doi.org/10.17487/rfc8362.
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Dulcos, Ronald, and Ned Shepherd. Structured Analysis/Design - LSA Task 101, Early Logistic Support Analysis Strategy, Subtask 101.2.1, Develop Early LSA Strategy. Fort Belvoir, VA: Defense Technical Information Center, July 1990. http://dx.doi.org/10.21236/ada255495.
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Shepherd, Ned, and Ronald Duclos. Structured Analysis /Design for the Logistic Support Analysis (LSA)Tasks, LSA Subtask 402.2.3, Impact of Resource Shortfalls. Fort Belvoir, VA: Defense Technical Information Center, January 1990. http://dx.doi.org/10.21236/ada255549.
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Levin, Esther, and Mehrbod Sharifi. Using LSA to Compute Word Sense Frequencies. Fort Belvoir, VA: Defense Technical Information Center, February 2008. http://dx.doi.org/10.21236/ada481480.
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Duclos, Ronald, and Ned Shepherd. Structured Analysis and Structured Design for the Logistic Support Analysis (LSA) Task, LSA Subtask 303.2.4, Sensitivity of System Readiness. Fort Belvoir, VA: Defense Technical Information Center, February 1990. http://dx.doi.org/10.21236/ada255288.
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