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排序方式: 共有1895条查询结果,搜索用时 15 毫秒
991.
Yoshikazu Fukuyama Yoshiteru Ueki Kazuhiro Kaneko 《Electrical Engineering in Japan》1992,112(3):80-88
In restoration of a power system, appropriate steps need to be taken in early stages to avoid damage to the public caused by insufficient power supply. The first step in the restoration is the analysis of the fault that has produced the power failure. Today, a large amount of data will be available at the occurrence of a fault due to the use of advanced communication systems using digital relays and optical fibers. Such systems are intended to obtain data from the relays and circuit breakers (CBs) under operation and the voltage and current during operation and the prefault and postfault periods. This paper presents a hybrid fault analyzing expert system using data based on protective devices and phasor measurement. This system is a combination of an artificial neural network (ANN) and an expert system (ES). The ANN is used to simplify the analysis of current and voltage waveforms, which is considered difficult due to the presence of a fault resistance and the line impedance. Since a fault waveforms contains various ambiguous factors depending on the nature of the fault resistance, load current and other system parameters, the use of ANN is effective making such determinations. 相似文献
992.
The developmental localization patterns of collagen type IV alpha1-5 chains, laminin-1, laminin-5, and laminin alpha2 chain were analyzed in the embryonic mouse eye using isoform specific antibodies and immunofluorescence microscopy. Laminin-1 isoform and alpha1-2(IV) were ubiquitously expressed along the ocular surface basement membranes at a very early stage of eye development. Alpha3-5(IV) were first detected at later stages of development, and exhibited a variable distribution pattern along the ocular surface basement membrane. In contrast, expression of the laminin alpha2 chain was restricted to the conjunctival basement membrane, and was first detected during the same developmental period in which keratin K4-positive, differentiated conjunctival epithelial cells were observed. Although laminin-5 was uniformly expressed along the adult ocular surface basement membrane, during embryogenesis it was first incorporated into the conjunctival basement membrane structure. These data suggest that some of the laminin isoforms, including laminin alpha2 and laminin-5, may play a role in the formation of a conjunctival-type basement membrane. The temporal relationship between the localization of these molecules to the conjunctival basement membrane and the appearance of differentiated conjunctival epithelial cells suggests a role for external influence on the differentiation pathways of ocular surface epithelium. 相似文献
993.
K Ochi T Ohashi H Kinoshita M Akagi H Kikuchi M Mitsui T Kaneko I Kato 《Canadian Metallurgical Quarterly》1997,100(9):915-919
We measured the serum zinc level in patients with tinnitus and evaluated the effectiveness of zinc in the treatment of tinnitus. Blood zinc levels were measured in 121 patients with tinnitus. All patients were examined between 1995 and 1997 at the outpatient clinic of otorhinolaryngology St. Marianna University Toyoko Hospital. Forty-seven patients who had received any drug such as a calcium channel blocker and others or had been affected by any diseases were excluded and therefore 74 patients consisting of 46 females (62%) and 28 males (38%) were investigated. Twenty two healthy volunteers served as a control group. The mean age and standard deviations for the tinnitus group and the control group were 47.8 +/- 17.1 and 31.4 +/- 8.2 years, respectively. There was a significant decrease (p < 0.0001) in serum zinc levels in patients with tinnitus compared with the control group. Because there was a significant difference (p < 0.0001) in age distribution between tinnitus and control groups, patients were selected by their age in order to neglect the effect of aging. In this situation, a significant difference (p < 0.01) was noted between the tinnitus group and control group. Low blood zinc level was defined by using the mean and standard deviation for the control group (mean-1 S.D.). We treated patients with low blood zinc levels. A total dose of 34-68 mg of Zn++ was administered daily for over 2 weeks. The degree of tinnitus was expressed on a numeric scale from 0 to 10 before and after treatment. Blood zinc levels were significantly elevated (p < 0.05) after treatment. We found a significant decrease (p < 0.01) in the numeric scale. These findings suggest that zinc is useful in at least some patients suffering from tinnitus. It is possible to classify patients with tinnitus by measuring serum zinc level and this leads to improvement of the overall treatment effect. 相似文献
994.
We consider the shortest‐path‐counting problem (SPCP), which asks how many shortest paths is each edge of a network contained in? There are n(n?1) shortest paths in a network with n nodes, so among all these shortest paths the SPCP requires us to count the number of shortest paths passing through each edge. We obtain theoretical results in the form of explicit expressions for special types of networks such as trees, grid type, circular type, etc. We apply the SPCP to measure the importance of city road segments, which will certainly contribute to estimate the traffic congestion of the city road segments. Then we propose a quantitative method for evaluating the stable connectedness of the network‐structured system using shortest‐path‐counting methods. We define the stable‐connection function and the expected stable‐connection function for the network‐structured system. Then we derive some theoretical results for some special types of network such as single path, cycle graph, and complete graph. Several properties and characteristics of the stable‐connection function are also shown with some theoretical results. We show the application of the Monte Carlo method to estimate the expected stable‐connection function. This method can be applied to measure the strength of connectedness of the Japanese road network system. 相似文献
995.
Fluid flow and mass transfer characteristics in an axisymmetric sinusoidal wavy‐walled tube are experimentally investigated in the Reynolds number range of 50 to 1000. Attention is paid to the transitional flow, which is observed in the Reynolds number range of 160 to 200. In the laminar flow regime, wall shear stress and mass transfer rate increase with the slopes of 1 and 1/3, respectively, whereas in the turbulent flow regime they increase with the slopes of 3/2 and 3/5, respectively. In the transitional flow regime they increase dramatically, with a sharp slope. It is found that in this flow regime, laminar‐like motion and turbulent‐like motion alternatively take place at different time intervals. This is quite different from the flow instability for the wavy‐walled channel, where Tollmien‐Schlichting waves are observed. The flow instability in the wavy‐walled tube in the transitional flow regime is considered to be responsible for a significant increase in the wall shear stress and mass transfer rate. © 2003 Wiley Periodicals, Inc. Heat Trans Asian Res, 32(7): 650–661, 2003; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/htj.10121 相似文献
996.
Zhang J Kumagai H Yamamura K Ohara S Takami S Morikawa A Shinjoh H Kaneko K Adschiri T Suda A 《Nano letters》2011,11(2):361-364
Herein we demonstrate the extra-low-temperature oxygen storage capacity (OSC) of cerium oxide nanocrystals with cubic (100) facets. A considerable OSC occurs at 150 °C without active species loading. This temperature is 250 °C lower than that of irregularly shaped cerium oxide. This result indicates that cubic (100) facets of cerium oxide have the characteristics to be a superior low-temperature catalyst. 相似文献
997.
998.
Hiroshi Yoshida Yoshihiro Miwa Masanobu Kaneko 《Applicable Algebra in Engineering, Communication and Computing》2011,22(2):147-164
Starting from an egg, the multicell becomes a set of cells comprising a variety of types to serve functions. This phenomenon
brings us a bio-motivated Lindenmayer system. To investigate conditions for a variety of cell types, we have constructed a
stochastic model over Lindenmayer systems. This model considers interactive behaviors among cells, yielding complicated polynomials.
Using symbolic computation, we have derived explicit relations between cell-type diversity and cell-type ratio constraint.
These relations exhibit elliptic curve- and Fibonacci number-related patterns. This is the first example of elliptic curves
to appear in the Lindenmayer context. A survey of the rational points and the quadratic irrational numbers on the derived
curves has revealed Fibonacci-related periodic and quasiperiodic patterns. Further we have found that in some region, there
are only two elliptic curve-related periodic patterns. 相似文献
999.
In the course of worldwide efforts to suppress global warming, the saving of energy becomes more important. Recently, LNG (liquefied natural gas) terminals in our country have received more than 50 million tons of LNG per year. Therefore, the utilization of the cryogenic exergy in connection with the regasification of LNG gains more and more importance. The aim of this paper is the recovery of the energy consumed in liquefaction using the MGT (mirror gas-turbine), which is a new kind of combined cycle of a conventional gas-turbine worked as a topping cycle and TG (inverted Brayton cycle) as a bottoming cycle. The optimum characteristics have been calculated and it is shown that this cycle is superior to the current-use gasification systems in employing seawater heat in terms of thermal efficiency and specific output. In the present cycle, the cold LNG is used to cool the exhaust gas from a turbine of a TG, and then the exergy of the liquefied natural gas is transformed, with a very high efficiency, to electric energy. The main feature of this new concept is the removal of an evaporation system using seawater. 相似文献
1000.
Kawai Y Noguchi J Akiyama K Takeno Y Fujiwara Y Kajita S Tsuji T Kikuchi K Kaneko H Kunieda T 《Reproduction (Cambridge, England)》2011,141(2):217-225
Development of the male gonads is a complex process with interaction of various cells in the gonads including germ, Sertoli, Leydig, and myoid cells. TF is a mutant rat strain showing male pseudohermaphroditism, with agenesis of Leydig cells and androgen deficiency controlled by an autosomal single recessive gene (mp). The mp locus was mapped on the distal region of rat chromosome 7 by linkage analysis, but the gene responsible for the mp mutation has not been identified. In this study, we performed fine linkage mapping and sequence analysis to determine the causative gene of the mp mutation, and performed an immunohistochemical study using a Leydig cell-specific marker to investigate detailed phenotypes of the mutant rats during the testicular development. As a result, we found a missense mutation of the gene encoding Desert hedgehog (Dhh) in the mutant rat, which could result in loss of function of the DHH signaling pathway. Histochemical examination revealed remarkably reduced number of fetal Leydig cells and lack of typical spindle-shaped adult Leydig cell in the mp/mp rats. These phenotypes resembled those of the Dhh-null mice. Additionally, testosterone levels were significantly lower in the mp/mp fetus, indicating androgen deficiency during embryonic development. These results indicate that the mutation of the Dhh gene may be responsible for the pseudohermaphrodite phenotypes of the mutant rat, and that the Dhh gene is probably essential for the development of Leydig cells. 相似文献