493 research outputs found
Baxter's inequality for fractional Brownian motion-type processes with Hurst index less than 1/2
The aim of this paper is to prove an analogue of Baxter's inequality for
fractional Brownian motion-type processes with Hurst index less than 1/2. This
inequality is concerned with the norm estimate of the difference between
finite- and infinite-past predictor coefficients.Comment: 7 page
Applications of a finite-dimensional duality principle to some prediction problems
Some of the most important results in prediction theory and time series
analysis when finitely many values are removed from or added to its infinite
past have been obtained using difficult and diverse techniques ranging from
duality in Hilbert spaces of analytic functions (Nakazi, 1984) to linear
regression in statistics (Box and Tiao, 1975). We unify these results via a
finite-dimensional duality lemma and elementary ideas from the linear algebra.
The approach reveals the inherent finite-dimensional character of many
difficult prediction problems, the role of duality and biorthogonality for a
finite set of random variables. The lemma is particularly useful when the
number of missing values is small, like one or two, as in the case of
Kolmogorov and Nakazi prediction problems. The stationarity of the underlying
process is not a requirement. It opens up the possibility of extending such
results to nonstationary processes.Comment: 15 page
The intersection of past and future for multivariate stationary processes
We consider an intersection of past and future property of multivariate
stationary processes which is the key to deriving various representation
theorems for their linear predictor coefficient matrices. We extend useful
spectral characterizations for this property from univariate processes to
multivariate processes.Comment: 8 page
Electrically controlled superconducting states at the heterointerface SrTiO/LaAlO
We study the symmetry of Cooper pair in a two-dimensional Hubbard model with
the Rashba-type spin-orbit interaction as a minimal model of electron gas
generated at a heterointerface of SrTiO/LaAlO. Solving the Eliashberg
equation based on the third-order perturbation theory, we find that the gap
function consists of the mixing of the spin-singlet -wave component and
the spin-triplet -wave one due to the broken inversion symmetry
originating from the Rashba-type spin-orbit interaction. The ratio of the
d-wave and the p-wave component continuously changes with the carrier
concentration. We propose that the pairing symmetry is controlled by tuning the
gate voltage.Comment: 4 pages, 4 figures; added reference
A Prediction Problem in L^2(w)
For a nonnegative integrable weight function w on the unit circle , we provide an expression for p = 2, in terms of the series coefficients of he outer function of w, for the weighted Lp distance inff T 1 − f|pwdμ, here μ is the normalized Lebesgue measure and f ranges over trigonometric olynomials with frequencies in [{. . . ,−3,−2,−1}\{−n}]∪{m}, m ≥ 0, n ≥ 2. he problem is open for p = 2
Histopathology and clinical results of carpal tunnel syndrome in idiopathic cases and hemodialysis patients
The results of the histological examinations of specimens of the tenosynovium of the flexor tendon, the epineurium and the transverse carpal ligament from two groups of Japanese patients with carpal tunnel syndrome (idiopathic and hemodialysis) were compared. Amyloid deposits, positively identified as β2-microglobulin, appeared in all patients in the long-term hemodialysis group, but in no patients in the idiopathic group. Although the pathogenesis differed between the two groups, both resulted in nerve compression in the carpal tunnel. Therefore, surgical release is considered beneficial for both groups.</p
High-resolution sequence stratigraphy in an incised-valley system on the basis of sedimentary organic matter, sulfur content and fossil diatom: An example from Miocene to Pliocene Tatsunokuchi Formation, Iwate Prefecture, Northeast Japan
This paper discusses relationship among depositional environments, origin of the sedimentary organic matter and diatom fossil assemblage, combined with sequence stratigraphy in an incised-valley system. Interpretation of the environments and their changes was based on sedimentary facies, total sulfur (TS) content, and diatom assemblages. The quantity and composition of organic matter were estimated for the environmental interpretation on the basis of the total organic carbon (TOC) content, reflected-light fluorescent microscopy, and stable carbon isotope ratios of the organic matter (δ13Corg). The Miocene to Pliocene Ishibane, Tatsunokuchi and Motohata formations in northeast Japan consist of estuarine and fluvial deposits that were formed during a rise and fall of sea level. The proportions of vitrinite and cutinite that are coarse-grained and terrestrial in origin are relatively high in fluvial deposits of the lowstand systems tract. The proportion of marine alginite, TOC content, and δ13Corg values increase upward in estuary deposits of the transgressive systems tract. This implies the increase in the influence of the sea and the estuarine bottom conditions becoming anoxic. The proportions of vitrinite and cutinite increase upward in the highstand systems tract, whereas the δ13Corg values and TOC content decrease upward. These reflect the strong influence of river discharge. Variations of diatom fossil assemblage of fresh water, brackish water, intertidal, coastal marine and open marine species indicate the same repetitions of transgression and regression in the Tatsunokuchi Formation. Therefore, the transgressive systems tract in the Tatsunokuchi Formation includes four cycles of transgression and regression, while highstand systems tract shows one cycle of transgression and regression. / 岩手県南部の北上市に分布する中新統~鮮新統の石羽根,竜の口,本畑層は,エスチュアリーと河川環境での堆積を示している.また,1回の海水準上昇と引き続く低下で堆積した地層で,低海水準期堆積体,海進期堆積体,高海水準期堆積体に区分できる.その周期は約100万年と推定できる.河川成堆積物からなる低海水準期堆積体では陸源有機物片を多く含み,有機物は低い安定炭素同位体比(δ13Corg)を示す.引き続くエスチュアリー環境を示す海進期堆積体では,上方に向かって,海棲有機物が増え,δ13Corgの値が大きくなり,さらに全有機炭素量も増加する傾向にある.海進初期ではこれらは,小さな増減を4回繰り返しているが,やがて最大海進面に向かって安定して増加するようになる.最大海進面より上位の高海水準期堆積体では陸源有機物量が増大し,δ13Corgと全有機炭素量は減少し,陸域からの物質供給が増加したことが示される.珪藻化石の淡水種,汽水種,潮間帯種,沿岸性種,外洋種の比率変化も同一の海進海退の繰り返しを竜の口層中に記録している.したがって,竜の口層の海進期堆積体は短周期の4回の海進海退と引き続く海進から構成され,一方,高海水準期堆積体は1回の海退を示す.これらは数10万年周期の海水準変動に対応するかもしれない.ArticleJournal of the Sedimentological Society of Japan. 70(2):63-69 (2011)journal articl
Scanning Tunneling Microscopy Measurements of the Local Work Function around Steps on the Au/Cu(111) Surface(STM-local states)
With a scanning tunneling microscope we have taken local work function images of the Au/Cu(111) surface. The local work function measured from large Au-covered terraces is in good agreement with the result obtained by non-local techniques, and the local work function around step edges is significantly lower than that on terraces. The experimental details of the local work function lowering around a step can be reproduced nicely with a simple simulation if a dipole moment row with a proper linear density is put at the center of the step and if the influence of the topographic change of the step due to formation of the dipole moment is taken into account. It is demonstrated that STM has the ability to reveal the details of how local work function varies around steps and other defects on metal surfaces
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