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181.
In this paper, we present a stable sound source tracking method based on two updating algorithm. In the method, an eigenvector spanning the signal subspace is updated by using the Projection Approximation Subspace Tracking (PAST) algorithm without the eigen‐decomposition of a correlation matrix. Then, a constrained minimization problem is formulated taking into account the stability, and the solution is determined successively by applying the Interior Point Least Square (IPLS) algorithm. As a result, stable tracking can be achieved without the peak search of a MUltiple SIgnal Classification (MUSIC) spectrum, which often requires enormous computational costs because many complex multiplying operations are involved. Several experimental results in real room environments have demonstrated the high accuracy and the low computational costs of the proposed method. © Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.  相似文献   
182.
A variety of process-based models have been developed for predicting nitrogen (N) dynamics in agro-ecosystem; however, no reliable models have been validated for N leaching from soils receiving a long-term application of different types of animal manure composts. The Leaching Estimation and Chemistry Model (LEACHM) was recently modified by incorporating the basic structure of Rothamsted Carbon Model for extending its ability to describe soil organic matter decomposition and subsequent N leaching in soils rich in organic matter. We evaluate the applicability of the modified LEACHM in cropped Yellow soils receiving 10-year application of cattle or swine manure compost in addition to chemical fertilizers, where high-frequency field monitoring data of soil water contents, soil N contents and leachate N concentrations were available for the last 3 years. Particular attention was paid to determine all input parameters from independent measurements, parameterization from known soil properties or databases without optimisation to fit the measured field data. The model reasonably predicted temporal changes in the soil NH4-N and NO3-N contents, and inorganic N concentrations in the leachate as well as their differences due to different manure compost/chemical fertilizer applications. The simulations of leached N concentration yielded a Willmott index of agreement (IA) of 0.62–0.68, with those for soil moisture, soil nitrate content and crop N uptake all within an acceptable IA range. In view of the good performance without site-specific calibrations, the modified LEACHM appears to be a valuable tool for predicting N leaching from cropped soils receiving long-term manure compost applications.  相似文献   
183.
The effects of polyethylene cup thickness, femoral head sizes (22, 28 and 32 mm) and fusion defects on wear were investigated on retrieved total hip prostheses. When the cup thickness was less than 9 mm, the larger the femoral head, the higher the linear wear rate; however, when the cup thickness was more than 9 mm, the larger the femoral head, the linear wear rate was lower. When the cup thickness was less than 11 mm, the volumetric wear rate increased with increasing size of the femoral head, and when it was more than 11 mm, the volumetric wear rate of the three kinds of the prosthetic cups approached the same values. The wear rate of the cross-linked cups irradiated by 100 Mrad were very low, with no correlation to cup thickness. When the cup thickness was less than 9 mm, the volumetric wear rate tended to increase with increasing number of fusion defects. Large diameter fusion defects diminished the tensile strength.  相似文献   
184.
The number of patients suffering from dementia in Japan has been estimated to exceed 1,250,000 and is expected to increase rapidly in the near future. It is quickly becoming a serious medical and social issue. Alzheimer's disease (AD) is a leading cause of dementia, and can be classified into two genetic categories: single-gene and polygenic diseases. Familial Alzheimer's disease (FAD) is classified as a single-gene disease, while sporadic AD is classified as a polygenic disease which involves multiple genetic and environmental factors. Using positional cloning, most of the genes which lead to FAD have recently been identified e.g., the amyloid precursor protein (APP) gene on chromosome 21, presenilin I on chromosome 14 and presenilin II on chromosome 1. Recent studies indicate that mutations in these genes can result in either overproduction of A beta or in production of A beta 1-42. Although the accumulation of A beta has been suggested to be the "primary cause" not only in FAD but also in sporadic AD, it remains unclear how neurodegeneration in AD is related to the accumulation of A beta. The discovery of ApoE4 as a major genetic risk factor for AD has created a new step of research on AD as a polygenic disease. Although it is confirmed that the presence of the ApoE4 allele greatly accelerates age at onset of AD, the role of ApoE4 as a risk factor for AD remains to be fully elucidated. Now that major genes involved in the pathogenesis of AD have been identified, future research should be directed toward elucidation of the molecular mechanisms of how these gene products are involved in the pathogenesis of AD on protein as well as cellular levels.  相似文献   
185.
Abstract

Patients with gait disorders often use bilateral crutches along with their own two legs. It is a kind of quadrupedalism. Crutch-assisted gait is usually described and evaluated qualitatively. In this study, we developed a system to quantify the spatial and temporal parameters for crutch-assisted quadrupedalism. Our system consists of walkway hardware and our originally developed software. We specifically extended the measurable area to 1200 mm × 4800 mm, large enough to measure crutch gait. Using our system, we could describe crutch gait precisely. Our system has a capability to evaluate differences between patients and changes within a patient.  相似文献   
186.
Poly(L -lactide) (PLLA) and poly(DL -lactide) (PDLLA) blends were crystallized from the melt and their crystallization behaviors and morphologies were investigated using differential scanning calorimetry and polarizing microscopy. PLLA could crystallize from the melt in the presence of PDLLA when the PLLA content in the blend (XPLLA) was higher than 0.2. Spherulites were formed when XPLLA was between 0.6 and 1. The radius of the spherulites formed in the presence of PDLLA was larger than that of nonblended PLLA, probably because the coexisting PDLLA reduced the density of nuclei for the spherulites. Small crystallite assemblies were formed when XPLLA was between 0.2 and 0.5, and grew spherically from the nuclei when XPLLA was 0.5. Isotactic PLLA and atactic PDLLA seem to be miscible prior to crystallization, but PDLLA will be trapped between the lamellae of the spherulites or spherulitic assemblies during crystallization. PDLLA delayed the induction for crystallization of the blends. In spite of different morphology, the melting temperature and crystallinity of PLLA remained virtually constant when annealing was conducted for 600 min at XPLLA between 0.5 and 1. © 1995 John Wiley & Sons, Inc.  相似文献   
187.
Changes in the gas composition during the methane chemical vapor deposition growth of single- and double-walled carbon nanotubes over metal-supported MgO catalysts were investigated in an attempt to increase the nanotube yield. Monitoring the gas composition by gas chromatography as a function of the reaction time provides information on the activity and lifetime of the catalyst. The degree of methane decomposition, i.e., the C-H bond dissociation, was closely related to the nanotube yield, and the Fe-Mo binary catalyst exhibited a high activity. The effects of water vapor on the catalytic nanotube growth were also studied by introducing water vapor in the inlet gas. An appropriate amount of water prolonged the lifetime of the catalyst and increased the nanotube yield by 35%.  相似文献   
188.
189.
Experimental study has been made during cure process of SBR/NR foam rubber. Rubber sample with 30 mm thick, made up by stacking thin rubber sheets in layers, was packed in a metal mold, and peroxide cure was performed by transient heat conduction. Rubber heating time was changed in several steps in order to study the effects of the cure time on the blowing characteristics. Also swelling test was conducted in order to study the relation between the cell structure and the crosslink density. Typical temperature field of one-dimensional, transient heat conduction was observed, and results of the observation studies showed that the cell structure changed depending on both the position from the heating surface and the heating time, and two extreme cell structure, open-cell foam, and closed-cell foam, was clearly observed. Image analyses of the cell structure showed that the porosity distribution increased with the increase of the distance from the heating surface, and the porosity was lower for longer heating time at a same position. Average area of the foam almost took similar results for the result of the porosity, and these various quantities were correlated to the crosslink density.  相似文献   
190.
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