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101.
102.
Tomio Chiba Mitsuyasu Kido Junzou Kawakami Katsuhiko Yoneda Tadao Kawai Kotaro Hirasawa 《Electrical Engineering in Japan》1994,114(5):31-43
Control and protection equipment in power systems requires higher sensitivity and operational reliability to meet today's changing power system requirements. The voltage-measuring deviation requirement for advanced voltage and var control equipment is less than 0.1 percent under conditions of harmonic distortion in the voltage waveform and power-system frequency variation. Studies on digital signal processing suitable for electric power systems showed that these requirements are satisfied using fast sampling and very fast 32-bit floating point operations by a Digital Signal Processor (DSP). This paper describes the design philosophy of a high-precision power system voltage-measuring method using fast sampled data. In addition, total voltage-measuring deviation characteristics under a combination of the techniques are described along with digital filter characteristics, frequency-measuring deviation characteristics, frequency variation versus gain-compensation characteristics of a digital filter, and peak value operating principles. 相似文献
103.
A new test-generation system (FUTURE) for large digital circuits (more than 10K gates) is based on a nine-valued FAN algorithm. Fault simulation adopts a concurrent simulation adopts a concurrent simulation technique. The system consists of four major modules: fault modeling, random pattern generation, algorithmic pattern generation, and fault simulation. The system can be a powerful CAD tool and effectively generate test patterns for large sequential circuits with Scan Path. 相似文献
104.
An automated method for analysis of in vivo proton magnetic resonance (MR) spectra and reconstruction of metabolite distributions from MR spectroscopic imaging (MRSI) data is described. A parametric spectral model using acquisition specific, a priori information is combined with a wavelet-based, nonparametric characterization of baseline signals. For image reconstruction, the initial fit estimates were additionally modified according to a priori spatial constraints. The automated fitting procedure was applied to four different examples of MRS data obtained at 1.5 T and 4.1 T. For analysis of major metabolites at medium TE values, the method was shown to perform reliably even in the presence of large baseline signals and relatively poor signal-to-noise ratios typical of in vivo proton MRSI. Identification of additional metabolites was also demonstrated for short TE data. Automated formation of metabolite images will greatly facilitate and expand the clinical applications of MR spectroscopic imaging. 相似文献
105.
Hiromasa Kawai Hideo Takeda Masato Ueda Seiichi Nagatomi 《International Journal of Pressure Vessels and Piping》1975,3(3):195-209
The pipelines used in a ship amount to tens of thousands of metres per ship, and so automatic welding of the pipelines has been widely applied from the viewpoint of saving labour. In most cases the automatic welding process has been used for the welding of butt-joints which can be applied to the pipes in rotary motion, and it has also been used for fillet-welding of the connection between flange and piping. In the butt-welding of fixed pipings, automatic welding processes are now being partly used for position welding but up to the present time automatic welding has seldom been applied to the various types of branch pipe joints in which the welded lines form three-dimensional curves.In recent years, great progress has been made in the technique of constructing steel pipe structures and in the development of practical gas cutting processes to prepare the curves needed for the various welded joints used in piping. This paper deals with various conditions and performance requirements needed for automatic welding, such as the selection of shapes of prepared edges of pipings to be welded, the control of welding positions, the control of welding torches in operation, and the solution and control of other production variables. 相似文献
106.
Shoji Suehiro Takeshi Yamada Thein Kyu Ken-Ichi Fujita Takeji Hashimoto Hiromichi Kawai 《Polymer Engineering and Science》1979,19(13):929-939
Dynamic x-ray diffraction is employed to scrutinize the structural origin of the α mechanical dispersion of a highdensity polyethylene having preferentially oriented rownucleated cylindritic texture around the machine direction (MD). Results indicate that the α1 dispersion is associated with two kinds of orientation processes of crystallites: (1) the orientation process involving the rotation of crystallites around the crystal b-axis (lamellar axis) dominates in the MD specimen; (2) the other process accompanying the rotation of crystallites or lamellar segments around their crystal a-axis dominates in the TD (transverse direction) specimen. The complex apparent crystal lattice compliances show no frequency dependence in the real component and no appreciable value in the imaginary component, indicating that the α1 process is definitely associated with the intercrystalline process, but not relavent to the intracrystal process. However, at elevated temperatures, the complex lattice compliances exhibit a remarkable frequency dependence, suggesting that the α2 dispersion concomitant to intracrystalline nature takes place in this time scale. The α2 dispersion was found to be more pronounced upon stretching along the lamellar axis (TD) than normal to it (MD). 相似文献
107.
We investigated the current/voltage characteristics of n+GaAs/undoped AlxGa1?xAs (200 A)/n+GaAs heterostructures grown by the metalorganic chemical vapour deposition (MOCVD) method between 77 K and 300 K. Both the voltage dependence and the temperature dependence of the current were in good agreement over a wide current range with the calculated results of the tunnelling and thermionic emission current. 相似文献
108.
S Kawasaki K Nagai S Maruyama M Murakami K Yoshizane Y Morokoshi K Kawai M Yamamoto M Soda 《Canadian Metallurgical Quarterly》1994,21(13):2256-2259
Regional chemotherapy was given 16 unresectable gastric cancer patients. Two types of the chemotherapy, intraperitoneal (IP) and intraaortic (IA) administration, were carried out. The control group was comprised of 17 patients. The response of the chemotherapy for primary tumor was 36.4% in the IP group and 20% in the IA one. Among these patients, 2 of 11 in IP and 1 of 5 in IA were able to resect the primary tumor. The 50% survival time of IP, IA and control was 347, 227 and 78 days, respectively. One-year survival rates of IP, IA and control were 68%, 29% and 0%, respectively. IP showed a significantly longer survival rate than controls (p < 0.001). All but one patient was able to stay at home. Intraperitoneal chemotherapy showed both local and systemic effects in unresectable gastric cancer. 相似文献
109.
Chronic infection/inflammation of the urinary tract is a significant risk factor for the development of bladder cancer. The present study examined the hypothesis that hydrogen peroxide (H202) and cytokines released during inflammation are involved in the enhancement of bladder carcinogenesis. Using growth in soft agar and tumorigenicity in athymic nude mice as indices of transformation, we examined the effect of H202 and cytokines on the enhancement of N-methyl-N-nitrosourea (MNU)-initiated transformation of MYP3 cells, an anchorage-dependent nontumorigenic rat bladder epithelial cell line. MYP3 cells pretreated with or without MNU were exposed to H202 (0.001 to 0.1 mM) daily for 1 week in monolayer culture and were then tested for growth in soft agar. A marked increase in colony numbers was observed in the cells that were MNU-initiated and exposed to H202 (P < 0.01). Furthermore, H202 exposure alone at 0.01 mM or 0.1 mM caused colony formation in soft agar. The transformants induced by MNU plus H202 or H202 alone formed high-grade transitional cell carcinomas when injected into nude mice. The growth of these transformants was stimulated by several cytokines (interleukin 1alpha, interleukin 6, and tumor necrosis factor-alpha) better than the parental cells both on a plastic surface and in soft agar. Our results indicate that H202 causes genetic change(s) to induce tumorigenic conversion in urothelial cells and that the transformants are stimulated to grow because of their selective response to several cytokines. We suggest that these mechanisms may be involved in the in vivo carcinogenesis associated with chronic urinary tract infection. 相似文献
110.
Y Hayakawa R Kawai K Otsuki M Kataoka A Matsuda 《Canadian Metallurgical Quarterly》1998,8(18):2559-2562
To investigate the stability of 2'-C-cyano-2'-deoxy-1-beta-D-arabino-pentafuranosylcytosine 3'-phosphoric acid, its thymidine ester was prepared via the phosphoramidite method using allyl protection for the phosphate function. This ester is stable under acidic conditions but extremely labile under basic conditions, decomposing with a cleavage of the internucleotide bond even at pH 7.3. 相似文献