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排序方式: 共有580条查询结果,搜索用时 879 毫秒
51.
52.
Mitsuru Sekioka 《Geothermics》1990,19(2)
The purpose of this review is to outline the present state of direct uses of geothermal energy in Japan as of April 1989. Firstly, the representative examples are briefly illustrated. Secondly, an analysis is carried out to characterize each application, with a diagram combining the inlet temperature with the flow rate of individual direct use facilities. Finally, the total installed thermal power and the total thermal energy used are estimated at 171 MWt and 107 MWt yr, respectively, resulting in a total average load factor of 63%. The oil saved by geothermal direct uses is also evaluated at 0.06% of national consumption. 相似文献
53.
Hideomi Ohtsubo Mitsuru Kitamura 《International journal for numerical methods in engineering》1990,29(2):223-244
A quantitative method of a posteriori error estimation based on finite element solutions is developed. The proposed method can estimate the error of solutions obtained by the finite element method for two-dimensional elastic problems with 4-node elements. Since the error is estimated element by element, the proposed method does not require a large memory or long computing time. Not only rectangular elements but also arbitrarily shaped 4-node elements can be used in this method for estimating the error in the finite element computation with high accuracy. The finite element solutions are improved by adding the estimated errors onto the original solutions. The proposed method can be utilized for any type of linear problem if an isoparametric finite element method is used. 相似文献
54.
Ryohei Kimura Akiyoshi Monma Jinsong Duan Mitsuru Uesugi 《Wireless Personal Communications》2006,38(1):27-42
Orthogonal frequency division multiplexing (OFDM) is robust against multi-path interference due to using a lot of low symbol rate sub-carriers. In order to mitigate the degradation due to multi-path interference, guard time interval (GI) is inserted into each OFDM symbol. However, redundant allocation to GI leads to loss of effective transmission power. We propose the Block-OFDM which can reduce the GI overhead ratio per frame compared with conventional OFDM. In Block-OFDM system frequency domain equalization (FDE) is carried out in order to remove multi-path interference. We evaluated Block-OFDM performance in a frequency selective fading channel and compared with that of conventional OFDM.
Ryohei Kimura received his B.E. and M.S degrees in communications engineering form Tohoku University, Sendai, Japan, in 2001 and 2003, respectively. In 2003, he joined Panasonic Mobile Communications Co., Ltd. His current research interests include such mobile communication technologies as OFDM and MIMO (MLD), and the like.
Akiyoshi Monma received his B.E. in communications engineering form Tohoku University, Sendai, Japan, in 1998. In 1998, he joined Panasonic Mobile Communications Sendai R&D Lab. Co., Ltd. His current research interests include such mobile communication technologies as OFDM and PAPR reduction, and the like.
Jinsong Duan received his B.E. and M.S. from Changsha Institute of Technology, China in 1987 and 1990. He received his Ph.D. from Osaka City University, Japan in 2000. From 2000–2003 he was with Mitsubishi Electric Corporation, where he engaged in research and development of WCDMA systems. From 2003, he joined Panasonic Mobile Communications Co., Ltd. His current interests include such mobile communication technologies as OFDM, MIMO, link adaptation, scheduling, and TDMA/FDMA/CDMA systems.
Mitsuru Uesugi received his B.E. degree from Waseda University in 1986 and received his Ph.D degree from Tohoku University in 2004, respectively. He is a general manager in the Mobile Communication Technology Development Center of Panasonic Mobile Communications Co., Ltd. His current research interests include such mobile communication technologies as equalization, interference cancellation, modulation method, and the like. 相似文献
55.
Mitsuru Uesaka Takuya NatsuiKiwoo Lee Katsuhiro DobashiTomohiko Yamamoto Takeshi FujiwaraHaito Zhu Kazuyuki DemachiEiji Tanabe Masashi YamamotoNaoki Nakamura Joichi KusanoToshiyasu Higo Shigeki FukudaMitsuhiro Yoshida Shuji Matsumoto 《Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment》2011,657(1):82-87
We are developing compact X-band linac X-ray sources for nondestructive evaluation and medicine. First, we develop a portable X-ray system by a 950 keV 9.4 GHz X-band linac to realize on-site inspection. We use a low power (250 kW) magnetron as an RF source for compactness of the whole system. Since the RF power source is quite small and the stored energy in the structure is also small, we faced the problem of beam loading and current/RF-power oscillation. We are analyzing the problem by the circuit model. We plan to use this system for erosion inspection of metal pipes of petrochemical complex. By adopting a side-coupling cavity design to avoid the oscillation, we have developed 6 MeV X-band (9.3 GHz) linac for pinpoint dynamic tracking cancer therapy. Furthermore, we are manufacturing 3.95 MeV X-band (9.3 GHz) linac X-ray source with flexible waveguides for on-site bridge inspection. Updated results and situations are presented. 相似文献
56.
Hae-Seok Lee Hiroshi Okada Akihiro Wakahara Akira Yoshida Takeshi Ohshima Hisayoshi Itoh Shirou Kawakita Mitsuru Imaizumi Sumio Matsuda 《Solar Energy Materials & Solar Cells》2003,75(1-2):57-63
High-energy proton irradiation (380 keV and 1 MeV) on the electrical properties of CuInSe2 (CIS) thin films has been investigated. The samples were epitaxially grown on GaAs (0 0 1) substrates by Radio Frequency sputtering. As the proton fluence exceeded 1×1013 cm−2, the carrier concentration and mobility of the CIS thin films were decreased. The carrier removal rate with proton fluence was estimated to be about 1000 cm−1. The electrical properties of CIS thin films before and after irradiation were studied between 80 and 300 K. From the temperature dependence of the carrier concentration in CIS thin films, we found ND=9.5×1016 cm−3, NA=3.7×1016 cm−3 and ED=21 meV from the fitting to the experimental data on the basis of the charge balance equation. After irradiation, a defect level was created, and NT=1×1017 cm−3 for a fluence of 3×1013 cm−2, NT=5.7×1017 cm−3 for a fluence of 1×1014 cm−2 and ET=95 meV were also obtained from the same fitting. The new defect, which acted as an electron trap, was due to proton irradiation, and the defect density was increased with proton fluence. 相似文献
57.
58.
Isao Furukawa Mitsuru Nomura Sadayasu Ono 《Signal Processing: Image Communication》1993,5(5-6):527-538
A hierarchical image coding algorithm based on sub-band coding and adaptive block-size multistage vector quantization (VQ) is proposed, and its coding performance is examined for super high definition (SHD) image. First, the concept on SHD image is briefly described. Next, the signal power spectrum is evaluated, and the sub-band analysis pattern is determined from its characteristics. Several quadrature mirror filters are examined from the viewpoints of reconstruction accuracy, coding gain, and low-pass signal quality. Then an optimum filter is selected for the sub-band analysis. The two-stage VQ using the adaptive bit allocation is also introduced to control quantization accuracy and to achieve high-quality image reproduction. Coding performance and hierarchical image reconstruction are demonstrated using SNR and some photographs. 相似文献
59.
K Mita M Nenoi M Morimyo H Tsuji S Ichimura M Sawai K Hamana 《Canadian Metallurgical Quarterly》1995,162(2):329-330
We have isolated a beta-tubulin-encoding cDNA clone of Bombyx mori from testes and determined the nucleotide sequence. Northern analyses showed that its expression is testis-specific and most active in the pupal stage. 相似文献
60.
Chil-Woo Lee Osamu Hasegawa Wiwat Wongwarawipat Hiroshi Dohi Mitsuru Ishizuka 《Journal of Visual Communication and Image Representation》1991,2(4)
This paper describes a system that can synthesize realistic sequential images of moving goldfish based on the image understanding result of real goldfish. To analyze and synthesize images in real-time, we have constructed a hardware system that consists of 32 paralell transputers with a high-speed visual-data interface called VIT (Visual Interface for Transpputer Network). The system is very flexible and powerful for various types of image processing because it can be extended according to the required computational cost. In the understanding process, we assume that the target object, a goldfish in this case, deforms its shape pliably in 3-D space and moves only in a two-dimensional direction. A modeling, called the Bone-Structured Solid Modeler, which is suitable for representing deformable objects such as living things, plays an important role in the understanding and synthesis processes of the deformable object. Three types of constraints for motion, namely, static, dynamic, and object, are utilized to verify the estimated pose and orientation of the object. In the motion synthesis process, realistic moving images are synthesized by controlling the model employing the motion understanding result. Simulation results are presented to show the effectiveness of the system. The technology discussed in this paper is expected to play a key role in the realization of future visual human interfaces. 相似文献