著者

Obane H. Okajima K. Oozeki T. Ishii T.

出版者

Institute of Electrical and Electronics Engineers

雑誌

IEEE journal of photovoltaics (ISSN:21563381)

巻号頁・発行日

vol.2, no.3, pp.341-347, 2012-07

被引用文献数

40 10

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Photovoltaic (PV) systems are often nonuniformly illuminated owing to shadows of neighboring buildings, trees, clouds, etc. In order to reduce the effect of shadows on solar panels, we propose the concept of a PV system with reconnection; this system consists of PV arrays that can be reconnected to minimize the mismatch loss, depending on the output of each of its module, measured at regular time intervals. In this study, the relationship between the output improvement with reconnection and the switching interval is shown. For a 3-kW PV system, under conditions of cloudlessness and cloudiness, a sharp difference in the output improvement relative to the switching interval is not observed. However, under the condition of shading, the output improvement sharply decreases relative to the switching interval; the output improvement at a 1-min switching interval is 0.15 kWh·h (+22.4%). For the 90-kW building-integrated photovoltaic system, during the summer solstice, a sharp difference in the output improvement relative to the switching interval is not observed. However, during the vernal equinox and winter solstice, when a large area of the PV system is shaded for a long period of time, the output improvement sharply decreases relative to the switching interval. The output improvement at a 1-min switching interval is 6.5 kWh·d (+2.9%) during the vernal equinox and 2.3 kWh·d (+3.7%) during winter solstice.

著者

今村 恵子 作山 攜子 藤井 正道 蓮村 元 三好 邦達 イマムラ ケイコ サクヤマ ケイコ フジイ マサミチ ハスムラ ゲン ミヨシ クニタチ Imamura K. Sakuyama K. Fujii M. Hasumura H. Miyoshi K.

出版者

日本医学放射線学会

雑誌

日本医学放射線学会雑誌 (ISSN:00480428)

巻号頁・発行日

vol.38, no.2, pp.111-119, 1978-02-25

著者

温 暁青 玉本 英夫 Saluja Kewal K. 樹下 行三

出版者

一般社団法人電子情報通信学会

雑誌

電子情報通信学会技術研究報告. FTS, フォールトトレラントシステム

巻号頁・発行日

vol.97, no.224, pp.23-29, 1997-08-19

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CMOS回路に発生する欠陥をよく表せる故障モデルとして, トランジスタ短絡故障モデルが多用されている. トランジスタ短絡故障モデルでは, 1つのMOSトランジスタにつき6つの故障が仮定されるため, 膨大な数のトランジスタ短絡故障を対象にしなけれげならない. 本稿では, 回路を構成するセル内に存在する等価故障の他, セル間に存在する等価故障をも発見することのできる新しい等価故障解析手法を提案した. ベンチマーク回路において実験した結果, 対象故障数を3分の1程度に減らすことができた. 本手法はI_<DDQ>テストによる故障検出と故障診断の効率化に役立つと思われる.

著者

NAKAMURA Tadas K.

出版者

一般社団法人日本物理学会

雑誌

Progress of theoretical physics (ISSN:0033068X)

巻号頁・発行日

vol.128, no.3, pp.463-475, 2012-09-25

参考文献数

25

被引用文献数

17

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It has been shown three different views in relativistic thermodynamics can be derived from the basic formulation proposed by van Kampen and Israel. The way to decompose energy-momentum into work and heat is not uniquely determined; the different choices result in different views. Also the definition of three dimensional volume causes ambiguity of thermodynamical quantities. The present paper shows various theories are obtained depending on the choice of these two factors.

著者

Benseman T. M. Koshelev A. E. Kwok W.-K. Welp U. Vlasko-Vlasov V. K. Kadowaki K. Minami H. Watanabe C.

出版者

American Institute of Physics

雑誌

Journal of applied physics (ISSN:00218979)

巻号頁・発行日

vol.113, no.13, pp.133902, 2013-04

被引用文献数

55

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Stacks of intrinsic Josephson junctions (IJJs) made from high-temperature superconductors such as Bi2Sr2CaCu2O8+δ (Bi-2212) (BSCCO) are a promising source of coherent continuous-wave terahertz radiation. It is thought that at electrical bias conditions under which THz-emission occurs, hot spots may form due to resistive self-heating, and that these spots may be highly beneficial for the generation of high levels of THz power. Here, we perform an imaging study of the temperature distribution at the surface of BSCCO stacks utilizing the temperature-dependent 612 nm fluorescence line of Eu3+ in a europium chelate. The images directly reveal a highly non-uniform temperature distribution in which the temperature in the middle of the stack can exceed the superconducting transition temperature by tens of Kelvin under biasing conditions typical for THz-emission.

著者

K.M.

出版者

公益社団法人 日本船舶海洋工学会

雑誌

造船協会雑纂

巻号頁・発行日

vol.187, pp.663-665, 1937

著者

Lengliné O. Enescu B. Peng Z. Shiomi K.

出版者

American Geophysical Union

雑誌

Geophysical research letters (ISSN:00948276)

巻号頁・発行日

vol.39, no.18, pp.L18309, 2012-09

被引用文献数

55

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The 2011, Mw9.0 Tohoku earthquake was followed by an abundant amount of seismicity providing a unique opportunity to analyze the triggering mechanism of great earthquakes. Although the Tohoku earthquake occurred close to a dense seismic network, many aftershocks that occurred in the first few hours after the mainshock are not recorded in the earthquake catalogs. Here we use a template waveform approach to recover as many as possible missing events in the first 12 hours following the Tohoku mainshock. Our analysis is able to detect about 1.4 times more events than those listed in the High Sensitivity Seismograph Network earthquake catalog. Combining our new dataset with earthquakes that occurred at latter times, we are able to observe a continuous decay of the aftershock rate and along strike expansion of aftershock area. We relate the latter observation to the occurrence of post-seismic slip over the deep interface.

著者

Ohki H. Takeda K. Aoki S. Hashimoto S. Kaneko T. Matsufuru H. Noaki J. Onogi T.

出版者

American Physical Society

雑誌

Physical review D (ISSN:15507998)

巻号頁・発行日

vol.87, no.3, pp.034509, 2013-02

被引用文献数

61

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We calculate the strange quark content of the nucleon ⟨N

著者

Hui-Fen Chiu Brian K. Chen Chun-Yuh Yang

出版者

日本疫学会

雑誌

Journal of Epidemiology (ISSN:09175040)

巻号頁・発行日

pp.JE20120155, (Released:2013-04-01)

参考文献数

22

被引用文献数

5 16

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Background: In this cohort study, we investigated whether a diagnosis of herpes zoster (HZ) was associated with a higher risk of subsequent cancer as compared with the Taiwanese general population.Methods: Data were obtained from the Taiwan National Health Insurance Research Database. In total, 38 743 patients who were aged 50 years or older and had received ambulatory care for HZ between 1997 and 2006 were identified as the study cohort; 116 229 age- and sex-matched patients without HZ were included as the comparison cohort. We used Cox proportional hazards regression models to estimate the hazard ratios (HRs) for subsequent cancer, after controlling for potential confounders.Results: The HR for subsequent cancer varied according to time since HZ diagnosis. The HR was 1.58 (95% CI, 1.38–1.80) within the first year, 1.30 (95% CI, 1.15–1.46) between 1 and 2 years, 1.10 (95% CI, 0.98–1.24) between 2 and 3 years, 1.02 (95% CI, 0.91–1.15) between 3 and 4 years, and 1.08 (95% CI, 0.96–1.21) between 4 and 5 years. The risk of subsequent cancer, particularly lung cancer, was significantly higher during the first 2 years after initial diagnosis of HZ.Conclusions: Our findings suggest that an HZ diagnosis is a marker of occult malignancy, particularly in lung cancer. The HRs for cancer decreased gradually over time and were no longer significant after 2 years of follow-up, which indicates that the association between HZ and cancer is likely due to detection bias.

著者

Nakamura K. Baba M. Ajmal Khan M. Du W. Sasase M. Hara K. O. Usami N. Toko K. Suemasu T.

出版者

American Institute of Physics

雑誌

Journal of applied physics (ISSN:00218979)

巻号頁・発行日

vol.113, no.5, pp.053511, 2013-02

被引用文献数

21 11

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A 180-nm-thick boron (B) layer was deposited on a 300-nm-thick a-axis-oriented BaSi2 epitaxial film grown by molecular beam epitaxy on Si(111) and was annealed at different temperatures in ultrahigh vacuum. The depth profiles of B were investigated using secondary ion mass spectrometry (SIMS) with O2+, and the diffusion coefficients of B were evaluated. The B profiles were reproduced well by taking both the lattice and the grain boundary (GB) diffusions into consideration. The cross-sectional transmission electron microscopy (TEM) image revealed that the GBs of the BaSi2 film were very sharp and normal to the sample surface. The plan-view TEM image exhibited that the grain size of the BaSi2 film was approximately 0.6 μm. The temperature dependence of lattice and GB diffusion coefficients was derived from the SIMS profiles, and their activation energies were found to be 4.6 eV and 4.4 eV, respectively.

著者

Khan M. Ajmal Hara K. O. Du W. Baba M. Nakamura K. Suzuno M. Toko K. Usami N. Suemasu T.

出版者

American Institute of Physics

雑誌

Applied physics letters (ISSN:00036951)

巻号頁・発行日

vol.102, no.11, pp.112107, 2013-03

被引用文献数

72 15

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B-doped p-BaSi2 layer growth by molecular beam epitaxy and the influence of rapid thermal annealing (RTA) on hole concentrations were presented. The hole concentration was controlled in the range between 1017 and 1020 cm−3 at room temperature by changing the temperature of the B Knudsen cell crucible. The acceptor level of the B atoms was estimated to be approximately 23 meV. High hole concentrations exceeding 1 × 1020 cm−3 were achieved via dopant activation using RTA at 800 °C in Ar. The activation efficiency was increased up to 10%.

著者

喜田 宏 YAMNIKOVA Sv 河岡 義裕 高田 礼人 岡崎 克則 SVETRANA Yam デメネフ V. ヤムニコバ S. ルボフ D.K. 伊藤 壽啓

出版者

北海道大学

雑誌

国際学術研究

巻号頁・発行日

1995

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平成7〜9年夏、カムチャッカ半島南端付近、ハバロフスク郊外のアムール河流域ならびにサハ自治共和国内のレナ河流域において水禽の糞便および湖沼水3,000検体を採取した。8年にはレナ河流域北緯63度30分のコベイスキー地区で採取した約900検体の水禽糞便からインフルエンザウイルスH4N6亜型19株、H4N9亜型1株、H11N1亜型1株、H11N6亜型2株、H11N9亜型8株を分離した。9年にはコベイスキー地区で採取した水禽糞便120検体およびヤク-ツク(北緯62度)で採取した鴨の糞便72検体からは各々H4N6亜型1株およびH3N8亜型5株が分離された。一方、レナ河流域北緯65度00分〜64度36分の四十諸鳥地域で採取した水禽糞便約1,400検体と湖沼水20検体からはウイルスが分離されなかった。カムチャッカ半島ならびにアムール河流域で採取した水禽糞便からインフルエンザウイルスは分離されなかった。以上の成績は、鴨の営巣湖沼がレナ河流域北緯63度付近に存在することを示唆する。平成8年と9年の10月に北海道宗谷地方において採取した480検体の水禽糞便材料からインフルエンザウイルスH1N1亜型、H5N3亜型、H5N4亜型、H6N1亜型、H6N7亜型、H8N1亜型、H8N3亜型、H9N2亜型ならびにH11N9亜型各1株を分離した。平成8年度および9年度にレナ河流域および北海道の水禽糞便から分離したインフルエンザウイルスのNP遺伝子の系統進化解析を実施した。その結果、調べた分離株すべてが新型インフルエンザウイルスの発生地である中国南部を含むアジア大陸に分布するウイルスの系統に属することが判明した。以上の成績は、新型インフルエンザウイルスの抗原亜型を予測するために、シベリアの水禽営巣地におけるインフルエンザウイルスの分布をさらに解明する必要があることを示している。

著者

YANG L. W. WRIGHT P. D. SHEN H. LU Y. BRUSENBACK P. R. KO S. K. CALDERON L. HARTZLER W. D. HAN W. Y. DUTTA M. CHANG W. H.

出版者

社団法人応用物理学会

雑誌

Japanese journal of applied physics. Pt. 2, Letters (ISSN:00214922)

巻号頁・発行日

vol.32, no.10, pp.L1400-L1402, 1993-10-01

被引用文献数

1

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Submicron heterojunction bipolar transistors (HBTs) with maximum frequency of oscillation, f_<MAX>, of 91 GHz have been fabricated using a self-aligned technique and a very heavily carbon-doped (10^<20> cm^<-3>) base layer. Since the quenching of photoluminescence (PL) intensity in heavily-doped Cabs is mainly due to nonradiative recombination in the bulk material, while contribution from surface recombination is negligible, the use of a heavily carbon-doped base layer in AlGaAs/GaAs HBTs minimizes the influence of surface recombination in the extrinsic base region. Thus, for HBTs with a heavily doped base layer, the "emitter size effect" (degradation of HBT current gain) is greatly reduced when the emitter width is scaled down to submicron (0.6 μm) dimensions.

著者

Akahira M. Shimizu A. Takeuchi K.

出版者

Università di Bologna

雑誌

Statistica (ISSN:19732201)

巻号頁・発行日

vol.65, no.4, pp.351-365, 2005

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In current physics experiments, there are many cases when the value of a parameter is theoretically assumed to be nonnegative or positive. In such cases, a combined Bayesian-frequentist approach to confidence intervals for a positive parameter is adopted in this paper, and the confidence intervals are constructed. Comparisons of the confidence intervals with ordinary and Bayesian ones are done in the normal cases.

著者

Yamagata K Arai C Sasaki H Takeuchi Y Onizawa K Yanagawa T Ishibashi N Karube R Shinozuka K Hasegawa Y Chiba S Bukawa H

出版者

Nature Publishing Group

雑誌

Bone marrow transplantation (ISSN:02683369)

巻号頁・発行日

vol.47, pp.725-730, 2012-05

被引用文献数

25 6

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Oral mucositis (OM) is a frequent adverse effect of allogenic or autologous hematopoietic SCT. It results from direct toxic injury to the mucosal epithelial cells by the immunosuppressive regimen. Here, we compared the incidence and severity of OM between a group of 24 patients who received proper oral management during hematopoietic SCT and a group of 24 who did not. The oral management group received pre-hematopoietic SCT instruction on oral care and an oral examination in the clean room. Differences in the incidence and severity of OM between the two groups were examined statistically. OM was observed in 14 (58.3%) patients in the oral management group and 22 (91.6%) in the control group. The median of the OM score was 1 for the oral management group (range 0 to 3) and 2 for the control group (range 0 to 3). There was a significant difference in the OM score (P<0.05) and in the incidence of OM between the two groups (P<0.01). This study shows that oral management may decrease the occurrence of OM. Our results also suggest that it is important to include an oral management provider on the hematopoietic SCT team.

著者

Takahashi Y. Hara K. Kim S. Ikegami Y. Takubo Y. Terada S. Unno Y. Mitsui S. Kamada S. Yamamura K.

出版者

Elsevier B.V.

雑誌

Nuclear instruments & methods in physics research. Section A (ISSN:01689002)

巻号頁・発行日

vol.699, pp.107-111, 2013-01

被引用文献数

1 1

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We are developing p-bulk microstrip sensors for the high luminosity upgrade of the LHC accelerator, HL-LHC. The stability of FZ (float zone) wafers available to Hamamatsu Photonics was examined by irradiating them at rates expected at the HL-LHC. They show degradation in the operational voltage at low dose but recover after the dose is accumulated. The instability is dependent on the bias voltage and dose rate, and also on the irradiation history. We have characterized the instability and attributed the cause to the charge concentration at the electrode edge. The strip isolation, which is degraded while in irradiation, is shown not to induce any practical problem for the operation.

著者

Hara K. Baccehtta N. Spalding W.J. Worm S.D.

出版者

Elsevier B.V.

雑誌

Nuclear instruments & methods in physics research. Section A (ISSN:01689002)

巻号頁・発行日

vol.699, pp.84-88, 2013-01

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On September 30, 2011, the Collider Detector at Fermilab (CDF) finished physics data-taking at the Tevatron proton–antiproton collider. The original CDF silicon tracking detector, proposed in 1981 (SVX) and later replaced and updated (SVX′), was again replaced for Run-2 in 2002–2011 (SVX-II, ISL, L00). These systems operated successfully for many years, performing essential roles in exploring physics at the energy frontier, most notably the discovery of the top quark.

著者

Gerlovin I. Ya. Dolgikh Yu. K. Eliseev S. A. Ovsyankin V. V. Efimov Yu. P. Petrov V. V. Ignatiev I. V. Kozin I. E. Masumoto Y.

出版者

American Physical Society

雑誌

Physical review B (ISSN:10980121)

巻号頁・発行日

vol.65, no.3, pp.035317, 2002-01

被引用文献数

21 17

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Picosecond kinetics of polarized resonant photoluminescence (PL) of HH excitons in the GaAs/AlGaAs superlattices is studied in an external magnetic field. The measurements were made in real time using a streak camera. For the magnetic field aligned along the heterostructure growth direction, the resonant PL exhibits oscillations in the degree of linear polarization. The oscillations are ascribed to quantum beats between sublevels of the optically active excitonic doublet split by the magnetic field. For the magnetic field aligned along the plane of the layers, the resonant PL is found to exhibit oscillations in circular polarization. These oscillations are related to beats between states of the optically active and optically inactive excitonic doublets. Experimental dependence of the oscillation frequency on the magnetic field strength and orientation has allowed us to determine the hole and electron g factors and the electron-hole exchange energy. Dynamics of the degree of circular polarization of the PL in magnetic field is used to measure the energy relaxation rate of the exciton spin states. In the magnetic field exceeding 1 T, the energy relaxation rate is shown to be magnetic-field independent and equal (1±0.2)×1010 s-1. This value is found to be much smaller than the spin phase relaxation rate determined from decay of the quantum beats in linear polarization. Unlike the energy relaxation rate, the latter grows linearly with the field strength and equals (5±0.5)×1010 s-1 at 5 T. It is concluded that the main mechanism responsible for loss of macroscopic spin coherence is the reversible dephasing within inhomogeneously broadened system.

著者

Li Y. J. Takeuchi O. Futaba D. N. Oigawa H. Miyake K. Shigekawa H. Kuk Y.

出版者

American Physical Society

雑誌

Physical review B (ISSN:01631829)

巻号頁・発行日

vol.65, no.11, pp.113306, 2002-03

被引用文献数

3

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Site-dependent adsorption structures of Xe atoms on a Si(111)-7×7 surface were studied by scanning tunneling microscopy at 8 K. Xe atoms initially adsorb as dimers on the site between a rest atom and its two neighboring center adatoms, and then near the corner adatom site. Similar structures were formed at both the faulted half (FH) and the unfaulted half (UH) of the 7×7 unit. The observed structure is in excellent agreement with that estimated by the rigid ball model, however, site-dependent bias dependence and different stabilities were observed for them, indicating the existence of different interactions between Xe and Si atoms in the 7×7 unit despite the stable electronic structure of Xe. Based on the results with thermal desorption spectroscopy, the adsorption energies are estimated to be 200 and 220 meV for FH and UH units, respectively.

著者

Kozin I. E. Davydov V. G. Ignatiev I. V. Kavokin A. V. Kavokin K. V. Malpuech G. Ren Hong-Wen Sugisaki M. Sugou S. Masumoto Y.

出版者

American Physical Society

雑誌

Physical review B (ISSN:10980121)

巻号頁・発行日

vol.65, no.24, pp.241312, 2002-06

被引用文献数

61 53

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Spins of resident electrons in charged quantum dots (QD’s) act as local magnets inducing the Zeeman splitting of excitons trapped into dots. This is evidenced by the observation of quantum beats in the linearly polarized time-resolved photoluminescence of a biased array of self-assembled InP QD’s. An external magnetic field is found to shorten the spin beats’ decay time keeping constant the frequency of the beats. A model using the pseudospin formalism allows one to attribute the observed quantum beats to the radiative decay of hot trions having two electrons that occupy different energy levels in a QD.