42 research outputs found
All-mode Renormalization for Tensor Network with Stochastic Noise
In usual (non-stochastic) tensor network calculations, the truncated singular
value decomposition (SVD) is often used for approximating a tensor, and it
causes systematic errors. By introducing stochastic noise in the approximation,
however, one can avoid such systematic errors at the expense of statistical
errors which can be straightforwardly controlled. Therefore in principle, exact
results can be obtained even at finite bond dimension up to the statistical
errors. A previous study of the unbiased method implemented in tensor
renormalization group (TRG) algorithm, however, showed that the statistical
errors for physical quantity are not negligible, and furthermore the
computational cost is linearly proportional to a system volume. In this paper,
we introduce a new way of stochastic noise such that the statistical error is
suppressed, and moreover, in order to reduce the computational cost we propose
common noise method whose cost is proportional to the logarithm of volume. We
find that the method provides better accuracy for the free energy compared with
the truncated SVD when applying to TRG for Ising model on square lattice.
Although the common noise method introduces systematic error originated from a
correlation of noises, we show that the error can be described by a simple
functional form in terms of the number of noises, thus the error can be
straightforwardly controlled in an actual analysis. We also apply the method to
the graph independent local truncation algorithm and show that the accuracy is
further improved.Comment: 34 pages, 19 figures, 2 tables, version published in Phys.Rev.
Principles of the magnetic resonance imaging movie method for articulatory movement : a review
Magnetic resonance imaging (MRI) has become a critical tool for dental examination. MRI has many advantages over radiographic examination methods, including the lack of a requirement for patient exposure and the ability to capture high-contrast images of various tissue and organ types. However, MRI also has several limitations, including long examination times and the existence of metallic or motion artifacts. A cardiac imaging method using cine sequences was developed in the 1990s. This technique allows for analysis of heart movement and functional blood flow. Moreover, this method has been applied in dentistry. Recent research involving 3T MRI has led to the achievement of a temporal resolution of <10 ms, surpassing the frame rate of typical video recording. The current review introduces the history and principles of the cine sequence method and its application to the oral and maxillofacial regions
Avaliação do monitor de medida de pressão arterial 0mron 705-CP para uso em adolescentes e adultos jovens
Alstiphyllanines I–O, ajmaline type alkaloids from Alstonia macrophylla showing vasorelaxant activity
Seven new ajmaline type alkaloids, alstiphyllanines I–O (1–7) were isolated from the leaves of Alstonia macrophylla together with six related alkaloids (8–13). Structures and stereochemistry of 1–7 were fully elucidated and characterized by 2D NMR analysis. A series of alstiphyllanines I–O (1–7) as well as the known ajmaline type alkaloids (8–13) showed that they relaxed phenylephrine (PE)-induced contractions against rat aortic ring. Among them, vincamedine (10) showed potent vasorelaxant activity, which may be mediated through inhibition of Ca2+ influx through voltage-dependent Ca2+ channels (VDCs) and/or receptor-operated Ca2+ channels (ROCs) as well as partially mediated the NO release from endothelial cells. The presence of substituents at both N-1 and C-17 may be important to show vasorelaxation activity
Abundant Occurrence of Basal Radial Glia in the Subventricular Zone of Embryonic Neocortex of a Lissencephalic Primate, the Common Marmoset Callithrix jacchus
Subventricular zone (SVZ) progenitors are a hallmark of the developing neocortex. Recent studies described a novel type of SVZ progenitor that retains a basal process at mitosis, sustains expression of radial glial markers, and is capable of self-renewal. These progenitors, referred to here as basal radial glia (bRG), occur at high relative abundance in the SVZ of gyrencephalic primates (human) and nonprimates (ferret) but not lissencephalic rodents (mouse). Here, we analyzed the occurrence of bRG cells in the embryonic neocortex of the common marmoset Callithrix jacchus, a near-lissencephalic primate. bRG cells, expressing Pax6, Sox2 (but not Tbr2), glutamate aspartate transporter, and glial fibrillary acidic protein and retaining a basal process at mitosis, occur at similar relative abundance in the marmoset SVZ as in human and ferret. The proportion of progenitors in M-phase was lower in embryonic marmoset than developing ferret neocortex, raising the possibility of a longer cell cycle. Fitting the gyrification indices of 26 anthropoid species to an evolutionary model suggested that the marmoset evolved from a gyrencephalic ancestor. Our results suggest that a high relative abundance of bRG cells may be necessary, but is not sufficient, for gyrencephaly and that the marmoset's lissencephaly evolved secondarily by changing progenitor parameters other than progenitor type
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Research and Design of a Routing Protocol in Large-Scale Wireless Sensor Networks
无线传感器网络,作为全球未来十大技术之一,集成了传感器技术、嵌入式计算技术、分布式信息处理和自组织网技术,可实时感知、采集、处理、传输网络分布区域内的各种信息数据,在军事国防、生物医疗、环境监测、抢险救灾、防恐反恐、危险区域远程控制等领域具有十分广阔的应用前景。 本文研究分析了无线传感器网络的已有路由协议,并针对大规模的无线传感器网络设计了一种树状路由协议,它根据节点地址信息来形成路由,从而简化了复杂繁冗的路由表查找和维护,节省了不必要的开销,提高了路由效率,实现了快速有效的数据传输。 为支持此路由协议本文提出了一种自适应动态地址分配算——ADAR(AdaptiveDynamicAddre...As one of the ten high technologies in the future, wireless sensor network, which is the integration of micro-sensors, embedded computing, modern network and Ad Hoc technologies, can apperceive, collect, process and transmit various information data within the region. It can be used in military defense, biomedical, environmental monitoring, disaster relief, counter-terrorism, remote control of haz...学位:工学硕士院系专业:信息科学与技术学院通信工程系_通信与信息系统学号:2332007115216
Comparison of blood pressure measurement in the office, at home and ambulatory blood pressure (ABP) in children with arterial hypertension
O diagnóstico e acompanhamento da hipertensão arterial (HA) no paciente pediátrico dependem da acurácia e da representatividade da medida da pressão arterial (PA). A monitorização ambulatorial da pressão arterial (MAPA), apesar de suas vantagens em relação à medida casual, apresenta custo elevado e pode trazer desconforto ao paciente. A medida residencial da pressão arterial (MRPA), apesar de pouco estudada na criança, apresenta-se como um alternativo potencial à MAPA. Os objetivos deste estudo foram comparar as medidas da PA aferidas no consultório, na MRPA, na Liga de Hipertensão e pela MAPA avaliando o efeito do ambiente/observador e determinando a freqüência de valores compatíveis com HA nessas 4 situações. Este estudo foi transversal,prospectivo e foram incluídos pacientes com HA e PA controlada ou não no consultório. Foram analisadas as médias das pressões arteriais sistólicas e diastólicas. A MRPA foi realizada com aparelho OMRON HEM 705 CP por 14 dias, em dois períodos (manhã ou tarde e noite). Na véspera do início da MRPA, o paciente compareceu à Liga de Hipertensão do HC-FMUSP para colocação do equipamento da MAPA (SPACELABS 90207). Foram analisados os dados de 40 pacientes (14 meninas e 26 meninos), idade média 12,1±3,6 anos. Não houve diferença estatística entre as médias das pressões sistólicas (ANOVA p=0,3100) e diastólicas (ANOVA p=0,7700) no consultório com as médias diurnas da MRPA e nem com as médias sistólicas (ANOVA p=0,8240) e diastólicas(ANOVA p=0,1530) do período noturno da MRPA. As médias das pressões sistólicas e diastólicas da Liga e da MAPA foram maiores do que as médias do consultório e da MRPA (p0,05). Na MAPA sono, os pacientes apresentaram maior freqüência de PA controlada do que na MRPA noturna. Dez pacientes apresentaram PA não controlada no consultório, a MAPA confirmou o diagnóstico em 7/10 (17,5%) pacientes, enquanto 5/10 (12,5%) confirmaram pela MRPA. Nesse grupo, a hipertensão do avental branco ocorreu em 3/10 (7,5%) pacientes diagnosticados pela MAPA e em 5/10 (12,5%) diagnosticados pela MRPA.Trinta pacientes apresentaram valores de PA controlados no consultório, destes 24/30 (60%) pacientes confirmaram o diagnóstico pela MAPA e 26/30 (65%) pela MRPA. A hipertensão mascarada ocorreu em 6/30 (15%) pacientes diagnosticados pela MAPA e em 4/30 (10%) diagnosticados pela MRPA. Nesse estudo demonstrou-se concordância entre MAPA e MRPA (teste de Mc Nemar p 0.05). The BP measurements during nightime ABPM showed a higher frequency of values compatible with hypertension than the night HBP one. Ten patients were diagnosed hypertension in the office, ABPM confirmed the diagnosis in 7 / 10 (17.5%) patients, while 5 / 10 (12.5%) were confirmed by HBP. In this group, white-coat hypertension occurred in 3 / 10 (7.5%) patients as diagnosed by the ABPM and 5 / 10 (12.5%) as diagnosed by HBP.Thirty patients presented BP values within normal limits in the office, 24 / 30 (60%) patients confirmed this diagnosis by ABPM and 26/30 (65%) by HBP. Masked hypertension was diagnosed in 6 / 30 (15%) patients diagnosed by the ABPM and in 4 / 30 (10%) by HBP. This study confirmed a correlation between ABPM and HBP measurements (Mc Nemar test p <0.01) with good reproducibility as evaluated by the Kappa index (0.557)