Coordinate-independent computations and differential equations

Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1997.Includes bibliographical references (v. 2, p. 512-514).by Kevin K. Lin.M.Eng

Unveiling multi-scale laser dynamics through time-stretch and time-lens spectroscopies

Spectro-temporal studies on the nonlinear physics of complex laser dynamics are essential in approaching its ultimate performance as well as understanding interdisciplinary problems. Unfortunately, it has long been limited by the insufficient spectro-temporal resolving power of conventional temporal and spectral analyzers, particularly when an indefinite optical signal ensemble contains polychromatic mixtures of continuous-wave (CW) and short pulse. In this work, we propose a real-time optical spectro-temporal analyzer (ROSTA) with three synchronized processing channels (i.e., multi-core) for single-shot studies on laser dynamics. It simultaneously provides temporal resolutions of ~70 ps in the time domain and 10’s ns (or 10’s MHz frame rate) in the spectral domain, as well as a high spectral resolution for multiscale optical inputs, i.e., ranging from CW to fs pulses. Its non-trivial record length of up to 6.4 ms enables continuous observations of non-repetitive optical events over an extensive time period ― equivalent to a propagation distance of ~1900 km. To showcase its practical applications, ROSTA is applied to visualize the onset of passive mode-locking of a fiber laser, and interesting phenomena, i.e., evolution from quasi-CW noise burst to strong shock, transition from fluctuation to mode-locking, and coexistence of CW and mode-locked pulses, have been spectro-temporally observed in a single-shot manner for the first time. It is anticipated that ROSTA will be a powerful technology for spectro-temporal optical diagnosis in different areas involving polychromatic transients

Effect of Ti seed layer on the magnetization reversal process of Co/NiFe/Al-oxide/NiFe junction films

科研費報告書収録論文(課題番号:13305001・基盤研究(A)(2) ・H13～H15/研究代表者:宮崎, 照宣/高品位微小トンネル接合へのスピン注入

The universality of synchrony: critical behavior in a discrete model of stochastic phase coupled oscillators

We present the simplest discrete model to date that leads to synchronization of stochastic phase-coupled oscillators. In the mean field limit, the model exhibits a Hopf bifurcation and global oscillatory behavior as coupling crosses a critical value. When coupling between units is strictly local, the model undergoes a continuous phase transition which we characterize numerically using finite-size scaling analysis. In particular, the onset of global synchrony is marked by signatures of the XY universality class, including the appropriate classical exponents $\beta$ and $\nu$, a lower critical dimension $d_{lc} = 2$, and an upper critical dimension $d_{uc}=4$.Comment: 4 pages, 4 figure

Recent progress on the accurate determination of the equation of state of neutron and nuclear matter

The problem of accurately determining the equation of state of nuclear and neutron matter at density near and beyond saturation is still an open challenge. In this paper we will review the most recent progress made by means of Quantum Monte Carlo calculations, which are at present the only ab-inito method capable to treat a sufficiently large number of particles to give meaningful estimates depending only on the choice of the nucleon-nucleon interaction. In particular, we will discuss the introduction of density-dependent interactions, the study of the temperature dependence of the equation of state, and the possibility of accurately studying the effect of the onset of hyperons by developing an accurate hyperon-nucleon and hyperon-nucleon-nucleon interaction.Comment: 3 figures, 1 table, to appear in the Proceedings of "XIII Convegno di Cortona su Problemi di Fisica Nucleare Teorica", Cortona (Italy), April 6-8, 201

Influence of Social Motivations on Spectator Consumption Behavior of a Formula One Grand Prix Event

The purpose of this study was to examine the relationship between spectator motivation and sport consumption behavior in the context of F-1 events. Respondents were spectators from three Formula One (F-1) races held in Shanghai, China. Through a structural equation modeling analysis, Achievement Seeking and Salubrious Effects were found to be related to repurchase intentions. Three motivating factors (i.e., Achievement Seeking, Entertainment, and Catharsis) were also found to be associated with Word-of-Mouth intentions concerning F-1 events

Rising Annual Costs of Dizziness Presentations to U.S. Emergency Departments

Objectives Dizziness and vertigo account for roughly 4% of chief symptoms in the emergency department ( ED ). Little is known about the aggregate costs of ED evaluations for these patients. The authors sought to estimate the annual national costs associated with ED visits for dizziness. Methods This cost study of adult U.S. ED visits presenting with dizziness or vertigo combined public‐use ED visit data (1995 to 2009) from the National Hospital Ambulatory Medical Care Survey ( NHAMCS ) and cost data (2003 to 2008) from the Medical Expenditure Panel Survey ( MEPS ). We calculated total visits, test utilization, and ED diagnoses from NHAMCS . Diagnosis groups were defined using the Healthcare Cost and Utilization Project's Clinical Classifications Software ( HCUP ‐ CCS ). Total visits and the proportion undergoing neuroimaging for future years were extrapolated using an autoregressive forecasting model. The average ED visit cost‐per‐diagnosis‐group from MEPS were calculated, adjusting to 2011 dollars using the Hospital Personal Health Care Expenditures price index. An overall weighted mean across the diagnostic groups was used to estimate total national costs. Year 2011 data are reported in 2011 dollars. Results The estimated number of 2011 US ED visits for dizziness or vertigo was 3.9 million (95% confidence interval [ CI ] = 3.6 to 4.2 million). The proportion undergoing diagnostic imaging by computed tomography ( CT ), magnetic resonance imaging ( MRI ), or both in 2011 was estimated to be 39.9% (39.4% CT , 2.3% MRI ). The mean per‐ ED ‐dizziness‐visit cost was $1,004 in 2011 dollars. The total extrapolated 2011 national costs were$3.9 billion. HCUP ‐ CCS key diagnostic groups for those presenting with dizziness and vertigo included the following (fraction of dizziness visits, cost‐per‐ ED ‐visit, attributable annual national costs): otologic/vestibular (25.7%; $768;$757 million), cardiovascular (16.5%, $1,489;$941 million), and cerebrovascular (3.1%; $1059;$127 million). Neuroimaging was estimated to account for about 12% of the total costs for dizziness visits in 2011 ( CT scans $360 million, MRI scans$110 million). Conclusions Total U.S. national costs for patients presenting with dizziness to the ED are substantial and are estimated to now exceed $4 billion per year (about 4% of total ED costs). Rising costs over time appear to reflect the rising prevalence of ED visits for dizziness and increased rates of imaging use. Future economic studies should focus on the specific breakdown of total costs, emphasizing areas of high cost and use that might be safely reduced. Resumen Incremento Anual de los Costes de las Atenciones por Mareo en los Servicios de Urgencias de Estados Unidos Objectivos El mareo y el vértigo suman aproximadamente el 4% de los motivos de consulta en el servicio de urgencias ( SU ). Se conoce poco sobre los costes globales de las evaluaciones del SU en estos pacientes. Se buscó estimar los costes anuales nacionales asociados con las visitas al SU por mareo. Metodología Este estudio de costes de visitas al SU de adultos norteamericanos que acudieron con mareo o vértigo combinó los datos públicos de las visitas a los SU (1995 a 2009) recogidos por el National Hospital Ambulatory Medical Care Survey ( NHAMCS ) y los costes (2003 a 2008) recogidos por el Medical Expenditure Panel Survey ( MEPS ). Se calcularon el total de visitas, el uso de pruebas diagnósticas y los diagnósticos del SU del NHAMCS . Los grupos diagnósticos se definieron según el Healthcare Cost and Utilization Project's Clinical Classifications Software ( HCUP ‐ CCS ). Los datos del año 2011 se documentaron en dólares de 2011. El total de visitas y la proporción de neuroimagen llevada a cabo en los futuros años se extrapoló usando un modelo predictivo autorregresivo. La media del coste por visita al SU por grupo diagnóstico del MEPS se calculó, ajustándose a dólares de 2011, mediante el índice de precios de los Hospital Personal Health Care Expenditures. Se utilizó una media ponderada global entre los grupos diagnósticos para estimar los costes totales nacionales. Resultados El número de visitas al SU en Estados Unidos en 2011 por mareo o vértigo fue de 3,9 millones ( IC 95% = 3,6 a 4,2 millones). El porcentaje de pruebas diagnósticas de imagen llevadas a cabo por tomografía computarizada ( TC ), resonancia magnética ( RM ) o ambas en 2011 se estimó en un 39,9% (39,4% TC , 2,3% RM ). La media de coste por visita al SU por mareo fue de 1.004 dólares de 2011. Los costes totales, extrapolados para todo el país, fueron de 3.900 millones de dólares. Los grupos diagnósticos HCUP ‐ CCS para aquéllos que presentaron mareo o vértigo incluyeron los siguientes (proporción de visitas por mareo; coste por visita al SU ; costes anuales nacionales atribuibles): otológico/vestibular (25,7%; 768 dólares; 757 millones de dólares), cardiovascular (16,5%, 1.489 dólares; 941 millones de dólares) y cerebrovascular (3,1%; 1.059 dólares; 127 millones de dólares). Se estimó una suma en la neuroimagen del 12% del total de costes para las visitas por mareo en 2011 (360 millones de dólares para la TC y 110 millones de dólares para la RM ). Conclusiones Los costes totales en Estados Unidos para los pacientes que acuden por mareo al SU son sustanciales, y se estima que sobrepasan en estos momentos los 4.000 millones de dólares por año (aproximadamente un 4% de los costes totales del SU ). El incremento de los costes con el paso del tiempo parece reflejar el crecimiento de la prevalencia de las visitas al SU por mareo y el aumento de porcentajes de utilización de la neuroimagen. Futuros estudios económicos deberían centrarse en el desglose de los costes totales, y hacer énfasis en las áreas de alto uso y coste que pueden ser reducidas sin riesgo.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/99059/1/acem12168.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/99059/2/acem12168-sup-0001-DataSupplementS1.pd

A global transcriptional network connecting noncoding mutations to changes in tumor gene expression.

Although cancer genomes are replete with noncoding mutations, the effects of these mutations remain poorly characterized. Here we perform an integrative analysis of 930 tumor whole genomes and matched transcriptomes, identifying a network of 193 noncoding loci in which mutations disrupt target gene expression. These 'somatic eQTLs' (expression quantitative trait loci) are frequently mutated in specific cancer tissues, and the majority can be validated in an independent cohort of 3,382 tumors. Among these, we find that the effects of noncoding mutations on DAAM1, MTG2 and HYI transcription are recapitulated in multiple cancer cell lines and that increasing DAAM1 expression leads to invasive cell migration. Collectively, the noncoding loci converge on a set of core pathways, permitting a classification of tumors into pathway-based subtypes. The somatic eQTL network is disrupted in 88% of tumors, suggesting widespread impact of noncoding mutations in cancer