Maximum Relative Height Research Articles

Surface integrity evolution of a Ni-based single crystal superalloy by laser shock peening

The single crystal superalloy SRR99 experimental samples were single point treated by laser shock peening (LSP) with laser pulse energy of 5–7 J. The surface morphology, micro-hardness, surface residual stress and surface microstructure of samples prior and after LSP were determined by corresponding characterization instrument. From the surface morphology, a circular pit was formed in surface, which due to the severe plastic deformation induced by LSP, and the diameter & maximum relative height of circular pit were increase with laser pulse energy. From the micro-hardness and residual stress test results of samples, these were increased after LSP treatment. In detail, the initial microhardness and residual stress were 398 HV and -498 MPa, with laser pulse energy of 5 J, the microhardness and residual stress were increased to 455 HV and -843 MPa, when the laser pulse energy was increased to 7 J, the microhardness and residual stress were increased to 512 HV and -942 MPa. In addition, the surface roughness of samples was increased too, which reflect the severe plastic deformation. By observing the microscopic morphology of the bottom of the pit, it is found that there are convex structure and crater shape defect structures on the bottom surface, and the formation of these structures may affect the surface roughness of the shock area. Although LSP caused certain degree of twist deformation of the shape of the γ' phase, the original strengthening method characteristics of the matrix phase and strengthening phase was not destroyed, which still maintained the creep strength and thermal fatigue properties of superalloy. The experiment show that LSP can cause significant work hardening effect on the surface of superalloy, and the generated high residual compressive stress can effectively delay the initiation and propagation of cracks. Therefore, LSP technology can effectively improve the fatigue life of single crystal blade components.

Extraction of branch factors and model construction for Larix plantation using terrestrial laser scanning (TLS).

Forest parameters could be estimated without damage using terrestrial laser scanning (TLS). In this study, 1266 sets of branch parameters, including branch height, branch chord length, branch length, branch angle, branch diameter and the branch arc height, of 26 Larix trees were extracted based on TLS using point cloud processing software in the way of human-computer interaction. The average of extracted maximum relative height of the branches was 0.83. The accuracy of the extracted branch attributes followed the order of branch height > branch chord length > branch length > branchdiameter (with the branch diameter >20 mm) > branch arc height. After dividing the crown into four parts, it proved that the density of the branches increased while the extraction ratio and precision of branches decreased with the increase of crown height. Due to the low accuracy of branch diameter extraction, we developed a base diameter prediction model using the branch chord length, the height of branch, diameter at breast height and tree height as independent variables. The measured, extracted and model predicted values of different base diameter were compared, and discovered that accuracy of model prediction was greater than that of extraction by TLS. For timber production, the most worthy wood was the middle and lower section of the tree. The method could accurately extract tree height, diameter at breast height (DBH) and the branch attributes with the relative branch height of less than 0.8, providing the parameters that are necessary to develop a wood quality model.

Assessment of Debris Flow Risk Factors Based on Meta-Analysis—Cases Study of Northwest and Southwest China

Debris flow is a type of special torrent containing numerous solid materials. With many types of factors affecting debris flow, there is no reliable basis for the selection of risk factors for debris flow risk assessment. Therefore, to study the factors affecting debris flow, exploring a reliable method for assessing the relative importance of these factors is a significant endeavor in debris flow prevention and control work. In this research, debris flow risk assessment was combined with meta-analysis to analyze quantitatively the relative importance of risk factors of debris flow in northwest and southwest China. The final relative importance of each factor in northwest China is as follows, maximum relative height difference > slope of main channel > maximum daily precipitation > ratio of longitudinal slope > drainage area > length of main channel. In addition, in southwest China, maximum relative height difference > maximum daily precipitation > slope of main channel > ratio of longitudinal slope > length of main channel > drainage area. The meta-analysis results were accurate, which can provide a reliable basis for the selection of debris flow risk factors in debris flow risk assessment. Furthermore, it provides strong support for the application of meta-analysis in risk assessment of other geological hazards.

Maximum relative height of elastic interfaces in random media

The distribution of the maximal relative height (MRH) of self-affine one-dimensional elastic interfaces in a random potential is studied. We analyze the ground-state configuration at zero driving force, and the critical configuration exactly at the depinning threshold, both for the random-manifold and random-periodic universality classes. These configurations are sampled by exact numerical methods, and their MRH distributions are compared with those with the same roughness exponent and boundary conditions, but produced by independent Fourier modes with normally distributed amplitudes. Using Pickands' theorem we derive an exact analytical description for the right tail of the latter. After properly rescaling the MRH distributions we find that corrections from the Gaussian independent modes approximation are, in general, small, as previously found for the average width distribution of depinning configurations. In the large size limit all corrections are finite except for the ground state in the random-periodic class whose MRH distribution becomes, for periodic boundary conditions, indistinguishable from the Airy distribution. We find that the MRH distributions are, in general, sensitive to changes of boundary conditions.

Maximum relative height of one-dimensional interfaces: from Rayleigh to Airydistribution

We introduce an alternative definition of the relative heighthκ(x) of a one-dimensional fluctuating interface indexed by a continuously varying real parameter0≤κ≤1. It interpolates between the height relative to the initial value (i.e. inx = 0)when κ = 0 and the height relative to the spatially averaged height forκ = 1. We compute exactlythe distribution Pκ(hm,L) of the maximum hm of these relative heights for systems of finite sizeL and periodic boundary conditions. One finds that it takes the scaling formPκ(hm,L) = L−1/2fκ(hmL−1/2) where thescaling function fκ(x) interpolates between the Rayleigh distribution forκ = 0 and the Airydistribution for κ = 1, the latter being the probability distribution of the area undera Brownian excursion over the unit interval. For arbitraryκ, onefinds that it is related to, albeit different from, the distribution of the area restricted to the interval[0,κ] under a Brownian excursion over the unit interval.

Analysis of the αβ T Cell Receptor Repertoire in Advanced Myelodysplastic Syndrome

Analysis of the αβ T cell receptor (TCR) repertoire in patients with myelodysplastic syndrome (MDS) using the technique of TCR β chain spectratyping has provided valuable insights into the pathophysiology of cytopenias in a subset of patients. TCR β chain spectratypes represent complex datasets, however, and statistical tools for their comprehensive analysis are limited. To enable global comparison of spectratype data from different individuals, we developed a robust statistical method based on k-means clustering analysis, and applied this method to analysis of the αβ TCR repertoires in the peripheral blood of 50 MDS patients and 23 age-matched healthy controls. From each of the 23 CDR3 length distributions (one for each of 23 Vβ families) comprising each spectratype, 4 features were extracted: the number of peaks in the distribution, the relative height of the largest peak, the skewness of the distribution, and the kurtosis. K-means clustering was applied at the Vβ family level to the extracted feature data from the CDR3 length distributions across the 73 subjects. This analysis typically identified two distinct clusters: a “normal” cluster characterized by a higher number of peaks, lower maximum relative height, lower skewness, and lower kurtosis, and a second “abnormal” cluster with the opposite characteristics. Thus, each CDR3 length distribution was classified as normal or abnormal according to its assignment to one of these two clusters. The mean number of abnormal CDR3 length distributions per individual was 1.6 (range, 0 to 5) for the age-matched controls and 3.7 (range, 1 to 18) (p=0.03) for the MDS patients. K-means clustering was also applied at the individual level to composite datasets consisting of the four features extracted from each of the 23 CRD3 length distributions in each individual's spectratype. This higher-level clustering again generated 2 clusters. The “normal” cluster contained all of the age-matched control subjects as well as 39 MDS patients, while the “abnormal” cluster contained the remaining 11 MDS patients, all of whom had profoundly abnormal TCR Vβ spectratypes. The median age in the abnormal group was higher than in the normal group, 67 versus 61 years, respectively (p=0.031). When the individuals in the two groups were analyzed according to the IPSS and WHO classification systems, 82% of patients in the abnormal group had high-risk disease (IPSS int-2 and high), compared with only 45% in the normal group (p=0.03), and 73% of patients in the abnormal group had advanced disease by WHO classification (>5% blasts), as opposed to 41% in the normal group (p=0.027). The 11 MDS patients in the abnormal cluster also had a higher median expression level of the Wilms' tumor-1 (WT1) gene, as determined by quantitative RT-PCR, in the peripheral blood (0.034 versus 0.0062, p=0.047), and a higher median bone marrow blast count (10% versus 2%, p=0.056). The two groups of MDS patients were evaluated for potential differences in three variables that could potentially confound the analysis of TCR Vβ spectratyping: peripheral blood lymphopenia, active infection, and a history of transfusion. The median peripheral blood lymphocyte count (1310 × 103/ml versus 1410 × 103/ml, respectively; p=0.37), a history of transfusion (70% versus 70%), and the incidence of MDS-related infection (27% versus 21%, respectively, p=0.69), as defined by a viral, fungal or bacterial infection identified after the diagnosis of MDS but before sample acquisition, were also not significantly different between the normal and abnormal groups. In order to evaluate the stability of spectratypes over time and during therapy, serial Vβ spectratyping analysis of bone marrow mononuclear cells was performed in 4 patients before and after treatment with azacytidine and etanercept. In all 4 cases, the spectratypes remained stably abnormal over months of observation, during which time 2 patients achieved complete and 2 achieved partial remissions of their disease. In conclusion, we have developed a new statistical algorithm for spectratyping analysis that enabled the identification of a group of MDS patients with high-risk disease and highly abnormal αβ TCR repertoires. These findings further highlight the biological and clinical heterogeneity of MDS and provide the rationale for further studies of the αβ TCR repertoire in MDS.

Extreme statistics for time series: Distribution of the maximum relative to the initial value

The extreme statistics of time signals is studied when the maximum is measured from the initial value. In the case of independent, identically distributed (iid) variables, we classify the limiting distribution of the maximum according to the properties of the parent distribution from which the variables are drawn. Then we turn to correlated periodic Gaussian signals with a 1/falpha power spectrum and study the distribution of the maximum relative height with respect to the initial height (MRHI). The exact MRHI distribution is derived for alpha=0 (iid variables), alpha=2 (random walk), alpha=4 (random acceleration), and alpha=infinity (single sinusoidal mode). For other, intermediate values of alpha , the distribution is determined from simulations. We find that the MRHI distribution is markedly different from the previously studied distribution of the maximum height relative to the average height for all alpha. The two main distinguishing features of the MRHI distribution are the much larger weight for small relative heights and the divergence at zero height for alpha>3. We also demonstrate that the boundary conditions affect the shape of the distribution by presenting exact results for some nonperiodic boundary conditions. Finally, we show that, for signals arising from time-translationally invariant distributions, the density of near extreme states is the same as the MRHI distribution. This is used in developing a scaling theory for the threshold singularities of the two distributions.

Universal asymptotic statistics of maximal relative height in one-dimensional solid-on-solid models

We study the probability density function P(h(m), L) of the maximum relative height h(m) in a wide class of one-dimensional solid-on-solid models of finite size L. For all these lattice models, in the large-L limit, a central limit argument shows that, for periodic boundary conditions, P(h(m), L) takes a universal scaling form P(h(m), L) approximately radical(12w(L))(-1) f(h(m)radical(12w(L))(-1), with w(L) the width of the fluctuating interface f(x) and the Airy distribution function. For one instance of these models, corresponding to the extremely anisotropic Ising model in two dimensions, this result is obtained by an exact computation using the transfer matrix technique, valid for any L > 0. These arguments and exact analytical calculations are supported by numerical simulations, which show in addition that the subleading scaling function is also universal, up to a nonuniversal amplitude, and simply given by the derivative of the Airy distribution function f'(x).

Eye-blow Fault Scarps at the Onikobe Basin

In 1953, the author observed clear eye-blow fault scarps cutting new compound fans at the north-eastern foot of Mt. Koshiba in the southern margin of the Onikobe Basin, Miyagi Prefecture. The fault scarp runs about 1km from WNW to ESE and the maximum relative height of the scarp is 10m. Other parallel scarps are seen at the western end of that.There are older fans at the upper part of new fans. The margins of the old fans are seemingly originated from old eye-blow fault scarps, because the end scarps of old fans are linear and are parallel to the former eye-blow fault scarps.

TECTONIC FORMS IN THE SOUTHWESTERN INA VALLEY IN NAGANO PREFECTURE, CENTRAL JAPAN

The Ina Valley between the Kiso Mountains and the Ina Mountains, is one of the typical intermount basins in the Honshu Island. The valley is situated along the southeastern border of the Inner Zone of the Southwestern Japan, and its general strike runs almost parallel with the Median Dislacation Line which is one of the main geotectoniclines in the Japanese Islands. The valley (300-1, 000 meters in altitude) is 80 kilometers long from Tatsuno where the water of the Tenryu River gathers to form the main river to Hiraoka where it dissects the southwestern margin of the Ina Mountains. It is 15 kilometers wide from Takato to Tengu at the longest stretch in the valley. The maximum relative height between the Kiso Mountains and the valley is over 2, 300 meters, on the other hand that between the Ina Nountains and the valley is about 1, 500 meters. Many typical river terraces and fans are widely distribute in the northern half of this valley, while lots of gorges and the remains of the old basin-floor are well developed in the southern half. At the famous Tenryu-kyo, situated on the northern part in the investigated area of this study, the Tenryu River has taken its antecedent course for the first time, and the river runs finally through the Akaishi Mountains. Under what condition was this long valley formed? Many previous works on this problem carried out, but the writter has limitted his discussion to the tectonicforms, the fault topographies and the valley-floor inclined toward the upper reaches of the Tenryu River, in the southwestern area of this valley. Discussing the topics, in this paper, at first thet tpographical features in this area are described (_??_ig. 1); secondly the stratigraphical succession and the distribution of rocks and strata are expressed (_??_ig. 2); thirdly the distribution of the faults and that of the Tsukue-yama beds, the indicator of the displaced valley-floor, are mentioned (Fig. 2, 3 and 4); forthly the topographical significances of the faults (Fig. 5, 6 and 8) and the valley-floor inclined toward the upper reaches of the Tenryu River are discussed (Fig. 7); finally the geomonphological significances of the Southwestern Ina Valley are examined. The main subjects are summarized as follows: 1. Judging from the distribution of the faults in this area, the Southwestern Ina Valley is a ramp valley (or a graben), it cannot be, however, concluded to be a typical one. 2. There are several minor block basins and block hills in this ramp valley. The writter thinks that the Oshimojo, the Tomikusa, the Komaba, the Sankochi anc the Yonegawa Basin are the examples of the former, and the Miho hills are that of the latter. 3. It seems probable that the valley-floor of this area, in total, was elevated in comparision with the base-levels of the area since late Miocene time. The amonnt of its up lift was, however, naturally smaller than those of the Kiso and the Ina Mountains. 4. The fault movements which have affected the topographies in this area probably began in early Pliocene time and have been contenuous ever since. Strictly speaking, the movements in the early Pliocene time can be correlated with Kobayashi's Tobe phase, and those in Pleistocene time can be done Stilie's Pasadena phase and Kobayashi's Shobudani phase. 5. Judging from the distribution of the Tsukue-yama beds, the valley-floor of this area was inclined toward the northwest, the upper reaches of the Tenryu River, after late Pliocene or early Pleistocene time. To be exact, the amount of the vertical displacement in the distance (10.5 kilometers) between Naka-yama and Tsukue-yama at Ryuto (the left bank of the Tenryu River) ranges 200-300 meters (Fig. 7-B(2)), while that in the distance (7.6 kilomers) between the west base of Nihonmatsu-yama atRyuto and Usui-bara at Ryusei (the righe bank of the river) ranges 250-300 meters.