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401.
Shusaku Tsumoto 《Information Sciences》2009,179(11):1615-4571
Chance discovery aims at understanding the meaning of functional dependency from the viewpoint of unexpected relations. One of the most important observations is that such a chance is hidden under a huge number of coocurrencies extracted from a given data. On the other hand, conventional data-mining methods are strongly dependent on frequencies and statistics rather than interestingness or unexpectedness. This paper discusses some limitations of ideas of statistical dependence, especially focusing on the formal characteristics of Simpson’s paradox from the viewpoint of linear algebra. Theoretical results show that such a Simpson’s paradox can be observed when a given contingency table as a matrix is not regular, in other words, the rank of a contingency matrix is not full. Thus, data-ordered evidence gives some limitations, which should be compensated by human-oriented reasoning. 相似文献
402.
Experimental study of the performance of porous materials to moderate the roof surface temperature by its evaporative cooling effect 总被引:1,自引:0,他引:1
The change of urban surfaces from permeable to impermeable materials, i.e. asphalt or concrete, has caused the rising of surface temperatures, particularly in densely developed cities. The consequences of this problem lead to higher energy consumption, especially for cooling purposes and other environment related issues. This paper aims to investigate the performance of several non-porous and porous potential roofing materials, to determine which ones might best be used to create a more effective system by utilizing their moisture absorption and evaporation capabilities. Here, four kinds of materials—pebbles, silica sand, volcanic ash, and siliceous shale—were tested to evaluate their moisture and thermal performance, including the effects from different particle sizes. First, the necessary physical properties and pore characteristics were obtained. Thus, each material, under simple boundary conditions, was evaluated in an evaporation experiment, to determine comparative moisture and thermal behavior. Next, cyclic experimentation was conducted, in which variations of temperature, relative humidity and simulated solar radiation were included. The measurement results showed that porous materials can satisfactorily lower surface temperature. Among the tested samples, siliceous shale of both small and large particle diameter was found to lower the daily average surface temperature by up to 6.8 and 8.6 °C, respectively. The better performance of large size particles could possibly be caused by the ventilation occurring within the material layers and high solar penetration through the large gaps between particles, which would release more latent heat when compared to materials of smaller particle size. Finally, analysis of surface energy balance suggested that water contents, solar absorptivity, and wind effects all have significant influences on cooling the surface temperature. 相似文献
403.
This paper describes a new passive thermal control device—a Reversible Thermal Panel (RTP), which changes its function reversibly from a radiator to solar absorber by deploying/stowing the radiator/absorber reversible fin. Parametric studies were conducted and the RTP configuration which satisfies the thermal requirements was determined. The RTP engineering model was fabricated using highly oriented graphite sheets, honeycomb base plate, and shape memory alloy. The heat rejection performances and autonomous thermal controllability were evaluated by thermal vacuum tests. The test results show the excellent performances of heat rejection, absorption, and autonomous thermal control for the RTP. © 2006 Wiley Periodicals, Inc. Heat Trans Asian Res, 35(7): 464–481, 2006; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/htj.20131 相似文献
404.
S. Itoh T. Takeshita Y. Fujii F. Kajino J. Kanzaki K. Kawagoe S. Kim H. Matsunaga H. Miyata A. Nagano R. Nakamura H. Ono A.L.C. Sanchez 《Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment》2008,589(3):370-382
We have constructed a shower maximum detector (SMD) using 1-cm wide scintillating strips. The SMD measures the position of electrons and photons in the electromagnetic calorimeter, and improves the e/π separation capability. We use avalanche photodiodes (APDs) to read out the scintillation light; they are directly attached to each end of a strip so as to construct a compact detector. We operate the SMD at room temperature. This report describes the structure of the SMD and its performance as measured in beam tests for future linear collider experiments. 相似文献
405.
Akira Nagano Tsuyoshi Yoshitake Takeshi Hara Kunihito Nagayama 《Diamond and Related Materials》2008,17(7-10):1199-1202
Ultrananocrystalline diamond (UNCD)/amorphous carbon (a-C) composite thin films were grown in ambient hydrogen by pulsed laser deposition using a graphite target, and their optical properties were determined by optical absorption spectroscopy and Raman scattering spectroscopy. Three optical bandgaps exist. Two bandgaps are indirect and their values were estimated to be 1.0 eV and 5.4 eV; these bandgaps correspond to the a-C surrounding the UNCDs and the UNCDs respectively. The third bandgap is direct and has a value of 2.2 eV, which significantly contributes to a large absorption coefficient, (106 cm− 1 at 3.0 eV). Possible origins of the third bandgaps are the grain boundaries (GBs) between the UNCDs and the a-C since they are specific to the UNCD/a-C composite films. The infrared absorption spectrum and the Raman scattering spectrum revealed the incorporation of hydrogen in the GBs. The hydrogen incorporated in the GBs might also have some influence on the appearance of the direct bandgap and its value. 相似文献
406.
Y. Hayashi S. Nagano H. Enomoto C.-P. Li Y. Sugimoto H.R. Ibrahim H. Hatta C. Takeda T. Aoki 《Journal of food science》2009,74(1):C68-C72
ABSTRACT: Egg white protein (EWP) was phosphorylated by dry-heating in the presence of pyrophosphate at pH 4 and 85 °C for 1 d, and the foaming properties of phosphorylated EWP (PP-EWP) were investigated. The phosphorus content of EWP increased to 0.71% as a result of phosphorylation. To estimate the foaming properties of EWP, the foams were prepared by 2 methods: bubbling of the 0.1% (w/v) protein solution and whipping of the 10% (w/w) protein solution with an electric mixer. The foaming power, which was defined as an initial conductivity of foam from 0.1% (w/v) protein solution, was a little higher in PP-EWP than in native EWP (N-EWP), and the foaming stability of PP-EWP was much higher than that of dry-heated EWP (DH-EWP) and N-EWP. The microscopic observation of foams from the 10% (w/w) solution showed that the foams of PP-EWP were finer and more uniform than those of N- and DH-EWP. Although there were no significant differences in the specific gravity and overrun of the foams between PP- and DH-EWP ( P < 0.05), the specific gravity and overrun of the foams from PP-EWP were smaller and higher, respectively, than that of the foams from N-EWP. The drainage volume was smaller in the foams from PP-EWP than in those from N- and DH-EWP. These results demonstrated that phosphorylation of EWP by dry-heating in the presence of pyrophosphate improved the foaming properties, and that it was more effective for the foam stability than for the foam formation. 相似文献
407.
K.Maekawa H.Nagai M.Iwashita M.Muramatsu K.Kubota K.Hinata A.Shiota T.Kokubo M.Hattori K.Mishima H.Nagano M.Kodera K.Tokushige 《电子工业专用设备》2005,34(3):69-73
We investigated single damascene integration with Porous MSQ (Methyl-Silsesqui-oxane, k value is 2.3) and Spin on Low k MSQ (k value is 2.9) as hard mask on Porous MSQ. Mechanical property of Low k material is improved by Electron Beam (EB) Cure technology. And also One time cure of stacked Low k is successful without any problem. On integration issue of Low k material, we demonstrated low damage resist strip process by using reducing gas chemistry and clarified mechanism of new Cu corrosion mode during CMP process. 相似文献
408.
Mitsutoshi Satoh Tadahiko Mashino Tetsuo Nagano Masaaki Hirobe Issei Takayanagi Katsuo Koike 《Fullerenes, Nanotubes and Carbon Nanostructures》2001,9(2):141-151
Inhibitory effects of newly synthesized fullerene C60 derivatives 1 (C60-bis(N,N-dimethylpyrrolidinium iodide)), 2 (C60-proline-N-acetic acid) and 3 (C60-ethylenediamine-N, N'-diacetic acid) on acetylcholine-induced relaxation in endothelium-intact rabbit thoracic aorta precontracted by phenylephrine (10-6 M) were studied. Fullerene C60 derivative 1 (3 × 10-6 M), 2 (10-5 M) and 3 (10-5 M) reduced the maximum amplitude of the acetylcholine-induced relaxation without significantly changing the pD2 values obtained from the concentration - response curves. In the presence of fullerene C60 derivative 1 (10-5 M) the acetylcholine-induced relaxation was eliminated and an acetylcholine-induced contraction was observed. These results suggest that fullerene C60 derivative 1 strongly inhibits endothelium (nitric oxide)-dependent acetylcholine-induced relaxation in thoracic aorta of rabbit. 相似文献
409.
Takao Katsura Katsunori Nagano Shigeaki Narita Sayaka Takeda Yasushi Nakamura Atsushi Okamoto 《Applied Thermal Engineering》2009,29(5-6):906-919
The authors introduce calculation algorithm of the temperatures of the ground and heat carrier fluid in multiple ground heat exchangers for pipe arrangement of ground source heat pump (GSHP) systems. First, the outline is explained. Next, in order to investigate possibility for the operation of the GSHP system with steel foundation piles and validate reproducibility of the value calculated by the design tool including the calculation algorithm, field tests of heating and heat extraction were conducted with a residential GSHP system using 25 steel foundation piles of 8 m long as ground heat exchangers. From a result of comparison between temperatures of the measurement in the test and calculation by using the design tool, it was confirmed that the tool could predict the temperatures with acceptable precision and speed for utilizing as a design tool. In addition, performance of GSHP systems with steel foundation piles in long term is predicted with the design tool. In moderate climate region, since the GSHP systems using multiple ground heat exchangers with short length can operate with high efficiency as well as the GSHP system using a single ground heat exchanger with long length, the GSHP systems with steel foundation piles have possibility to become popular. 相似文献
410.
Takahashi Y. Nagano K. Takasaki Y. 《Selected Areas in Communications, IEEE Journal on》1990,8(7):1382-1386
Optical receivers for multichannel TV transmission in the VHF band are analyzed and tested from the viewpoints of linearity, sensitivity, and frequency response. Photodiodes and avalanche photodiodes are compared for use as a front-end detector. Optimization of the preamplifiers is studied in terms of both configurations and biasing conditions. Improvement of frequency characteristics, using a Percival coil, is also investigated. It is concluded that a receiver using a photodiode can attain as high a sensitivity as and a greater linearity (around 5 dB) than one using an avalanche photodiode 相似文献