著者

星野 豊 HOSHINO Yutaka

出版者

末川民事法研究会

雑誌

末川民事法研究 (ISSN:24328456)

巻号頁・発行日

vol.1, pp.1-11, 2017-07

著者

小松 和暉 宮路 祐一 上原 秀幸

出版者

IEEE

雑誌

IEEE Transactions on Wireless Communications = IEEE Transactions on Wireless Communications (ISSN:15361276)

巻号頁・発行日

vol.19, no.7, pp.4424-4438, 2020-07

被引用文献数

41

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This paper presents an iterative estimation and cancellation technique for nonlinear in-band full-duplex transceivers with IQ imbalances and amplifier nonlinearities. The estimation process of the proposed scheme consists of three stages, namely, the channel response estimation, IQ imbalance estimation, and power amplifier and low-noise amplifier (LNA) nonlinearities estimation. For the estimation of the parameters and improvement of the accuracy, distortions are compensated by cancellation or inversion with the latest estimated parameters. On the one hand, the channel response is estimated on the time domain; on the other hand, the IQ imbalance and nonlinearities are estimated on the frequency domain for a more straightforward estimation and superior accuracy. In the cancellation process of the proposed scheme, the received signal is compensated with the estimated parameters of the LNA and receiver IQ imbalance before cancellation because the desired signal is received with a high-power self-interference and is distorted by the radiofrequency receiver impairments. Simulation results show that the proposed technique can achieve higher cancellation performance compared with the Hammerstein canceller when the LNA is saturated by the self-interference. Additionally, the performance of the proposed canceller converges much faster than that of the Hammerstein canceller.

著者

藤栄 剛 仙田 徹志

出版者

日本フードシステム学会

雑誌

フードシステム研究 (ISSN:13410296)

巻号頁・発行日

vol.27, no.1, pp.17-31, 2020 (Released:2020-07-09)

参考文献数

20

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The purpose of this article is to investigate the structure of market channels and the impacts of the direct marketing on farm sales, focusing on the top one percent rice farms (large rice farms). We have used the agricultural census farm-level data, to which was applied propensity score matching. Our findings in this article are as follows. Firstly, more than half the large rice farms used multiple marketing channels and the number of market channels used were increasing. Secondly, direct marketing to consumers by farms ranked second and shipment to agricultural cooperatives ranked first for both large rice farms and all rice farms. Thirdly, in recent years, for large rice farms, the ratio of the implementation of direct marketing to consumers has been decreasing and the farms are changing shipping destinations from the direct marketing to consumers to retail sellers, food manufacturers and the food-service industry. Fourthly, the results of propensity score matching indicate that direct marketing to consumers increases farm sales for family-owned management entities, while this is not valid for organized management entities.

著者

北川 紀男 Norio Kitagawa

雑誌

桃山学院大学社会学論集 = ST. ANDREW'S UNIVERSITY SOCIOLOGICAL REVIEW (ISSN:02876647)

巻号頁・発行日

vol.4, no.1, pp.1-14, 1970-07-01

著者

北川 紀男 Norio Kitagawa

出版者

桃山学院大学総合研究所

雑誌

桃山学院大学社会学論集 (ISSN:02876647)

巻号頁・発行日

vol.4, no.1, pp.1-14, 1970-07

著者

田中 真砂子

出版者

一般社団法人 日本家政学会

雑誌

日本家政学会誌 (ISSN:09135227)

巻号頁・発行日

vol.38, no.7, pp.671-673, 1987-07-20 (Released:2010-03-10)

著者

竹内 千代子

出版者

聖トマス大学

雑誌

サピエンチア 聖トマス大学論叢 (ISSN:02862204)

巻号頁・発行日

no.45, pp.28-55, 2011-02

著者

西條 政幸

出版者

日本神経感染症学会

雑誌

神経感染症 (ISSN:13482718)

巻号頁・発行日

vol.25, no.1, pp.M1, 2020 (Released:2020-05-13)

著者

鹿 錫俊 Xijun LU

雑誌

北東アジア研究 (ISSN:13463810)

巻号頁・発行日

vol.16, pp.55-76, 2008-12-10

著者

鹿 錫俊 Xijun LU

雑誌

総合政策論叢 (ISSN:13463829)

巻号頁・発行日

vol.3, pp.61-74, 2002-03-25

著者

鹿 錫俊 Xijun LU

雑誌

北東アジア研究 (ISSN:13463810)

巻号頁・発行日

vol.6, pp.35-55, 2004-01-31

著者

鹿 錫俊 Xijun LU

雑誌

北東アジア研究 (ISSN:13463810)

巻号頁・発行日

vol.1, pp.17-41, 2001-03-30

著者

石 源華 許 建珍 鹿 錫俊 Yunhua SHI Jianzhen XU Xijun LU

雑誌

北東アジア研究 (ISSN:13463810)

巻号頁・発行日

vol.2, pp.33-48, 2001-10-01

著者

鹿 錫俊

出版者

一橋大学

巻号頁・発行日

1998

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博士論文

著者

小田 琢三

出版者

一般社団法人 日本生物物理学会

雑誌

生物物理 (ISSN:05824052)

巻号頁・発行日

vol.20, no.3, pp.163-173, 1980-05-25 (Released:2009-05-25)

参考文献数

128

著者

清水 直樹

出版者

立命館大学政策科学会

雑誌

政策科学 (ISSN:09194851)

巻号頁・発行日

vol.27, no.4, pp.99-117, 2020-03

著者

井上 剛宏

出版者

環境コミュニケーションズ

雑誌

緑の読本

巻号頁・発行日

no.65, pp.63-66, 2003-03

著者

遠藤 毅 中村 正明

出版者

Japan Society of Civil Engineers

雑誌

土木学会論文集 (ISSN:02897806)

巻号頁・発行日

vol.2000, no.652, pp.185-194, 2000-06-21 (Released:2010-08-24)

参考文献数

10

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我が国産業・経済の中心である東京都区部地域について, 深部地盤の地質層序・地質構造・地層の土質特性等の調査研究を進めるなかで, シルト層の圧密降伏応力, 一軸圧縮強度等の力学的特性の分布が地域別に分類されることを明らかした. 本文は, このシルト層の圧密降伏応力, 一軸圧縮強度等の力学的特性の地域的分布についてさらに検討を加えるとともに, 過圧密比 (OCR) を用い, 過去において現地盤の上位に発達していたと推測される地層の最大層厚を算出し, その層厚および深部地盤構造と土質特性との関係について広域的な検討を行い, シルト層の力学的特性の地域的な差異をもたらした原因を検討したものである.

著者

三反畑 修 綿田 辰吾 佐竹 健治 金森 博雄 Rivera Luis Zhan Zhongwen

雑誌

JpGU-AGU Joint Meeting 2020

巻号頁・発行日

2020-03-13

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1. IntroductionAlmost every decade, volcanic tsunami earthquakes occurred at a submarine volcano named Smith Caldera near Torishima Island in Japan (Torishima earthquakes). These earthquakes generated disproportionately large tsunamis for their seismic magnitudes (Mw 5-6) [e.g. Fukao et al., 2018, Sci. Adv.]. In order to determine their physical mechanism, we constructed a kinematic source model based on analyses of tsunamis and long-period seismic waves. Here, we present the detail of kinematic source modeling of the 2015 Torishima earthquake. The overview of the project, including the physical mechanism, characteristic seismic properties, causes of tsunami earthquake nature and similarities of recurrent earthquakes, will be presented by Sandanbata et al. in "Active Volcanism (S-VC45)" session.2. Hypothetical fault systems inferred from initial sea-surface displacementWe started the kinematic source modeling of the 2015 Torishima earthquake by estimating the initial sea-surface displacement around Smith Caldera by the tsunami waveform inversion. We used tsunami waveforms recorded at ocean-bottom pressure gauges deployed in the southern oceanic region of Japan, such as a temporary array [Fukao et al., 2018], DONET, the Deep Sea Floor Observatory off Muroto Cape, and the DART system. We found (1) a large uplift concentrated just over the caldera floor, and (2) clear peripheral subsidence at least along the northern side of the rim structure.Based on the results, we hypothesized a sub-caldera fault system composed of ring and horizontal faults (Fig.a). In the following sections, we examine whether the hypothetical fault system explains both tsunami and long-period seismic records. We also investigate the detailed fault geometries employing multiple fault models with variable fault parameters (i.e. depth of the horizontal fault, dip angle and length of the ring fault).3. Inversion of tsunami waveforms for slip distributions of sub-caldera ring and horizontal faultsWe determined slip distributions on the sub-caldera ring and horizontal faults from the tsunami records by applying a new efficient technique for computing tsunami Green's functions from subfault slips. In most cases, inverted slip distributions consist of thrust slip on an inward-dipping ring fault and asymmetric opening and closing of a horizontal fault (Fig.a).The slip distributions on the multiple fault models accurately reproduce the tsunami records (Fig.b), indicating that these are plausible models for explaining tsunami excitation of the Torishima earthquake. However, if the ring fault extends to a horizontal fault lying at a depth of about 4 km below the caldera floor, slip direction of the ring fault becomes opposite between the upper and lower half portions, which we consider unrealistic. Hence, we believe that the horizontal fault lies at a shallower depth of approximately 2 km.4. Forward modeling of long-period seismic waves from slip distributionsFinally, we investigated the plausibility of the slip models by comparing long-period seismic records at the F-net and GSN stations with their synthetic waveforms. Among the slip models, one with a ring fault with a 75° dip angle extending along an approximately three-quarter portion of the rim structure can best reproduce the observed long-period seismic waves (Fig.c). The waveforms of horizontal components and overall amplitude are sensitive to dip angle and length of the ring fault, respectively. This helps us to constrain the detailed fault parameters well.5. ConclusionWe concluded that the slip model thus obtained can explain quantitatively both tsunami and long-period seismic records, and is a good kinematic source model of the 2015 Torishima volcanic tsunami earthquake. The source model consists of thrust slip on inwardly down-dipping ring fault extending partially along the rim and asymmetric opening and closing of a sub-caldera horizontal fault is attributed to the trapdoor faulting at the active submarine caldera.

著者

三反畑 修 綿田 辰吾 佐竹 健治 金森 博雄 Rivera Luis Zhan Zhongwen

雑誌

JpGU-AGU Joint Meeting 2020

巻号頁・発行日

2020-03-13

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1. IntroductionAnomalous volcanic earthquakes repeatedly occurred about once every decade at submarine calderas near Torishima Island in Japan (Torishima earthquakes) [e.g. Fukao et al., 2018, Sci. Adv.] and near Curtis Island in New Zealand [Sandanbata et al., 2019, JpGU]. Despite their moderate seismic magnitudes Mw 5-6, the earthquakes generated disproportionately large tsunamis. Their moment tensors were dominated by non-double-couple (NDC) components. Considering their volcanic origin and efficient tsunami excitation, they are called as volcanic tsunami earthquakes. The mechanism of these events remains unresolved. Here, we present an overview of this project to determine the physical mechanism and characteristic features of these events. The details of kinematic source modeling will be presented by Sandanbata et al. in "Tsunami and tsunami forecast (H-DS08)" session.2. Physical mechanism inferred from kinematic source modelFrom the analyses of tsunamis and long-period seismic waves, we successfully constructed a kinematic source model of the 2015 Torishima earthquake (Fig.a). This model can explain quantitatively both tsunami and long-period seismic waves. The model consists of thrust slip on inwardly down-dipping ring faults extending partially along the rim and asymmetric opening and closing of a sub-caldera horizontal fault (Fig.b). In this model, thrust slip on a partial ring fault is caused by highly-pressurized magma inside a sill-like chamber below the caldera floor. This mechanism is similar to the trapdoor faulting observed geodetically at Sierra Negra caldera, Galápagos [e.g. Jónsson, 2009, Tectonophysics].3. Characteristic properties of long-period seismic excitationsWe next examine their long-period seismic excitations from this source. It is generally known from seismic excitation theory that the moment tensor components, Mrt and Mrp, and the volumetric change of a sill-like chamber at a shallow depth do not significantly contribute to seismic excitation [e.g. Kanamori & Given, 1981, PEPI]. In addition, the ring-fault slip partially eliminates its long-period seismic radiation due to cancellation of excitations from double-couple (DC) components from different portions of the ring fault [Ekström, 1994, EPSL]. These properties not only explain the NDC-type moment tensors of these events but also play an important role in the tsunami earthquake natures. The curved fault geometry focusing deformation just over the caldera also amplifies tsunamis.We demonstrate that the observable moment tensor components (other than Mrt and Mrp) reflect source geometries, arc length and orientation of the ring faults. The similarities of the observable source parameters of most of the recurrent volcanic tsunami earthquakes suggest that the trapdoor faulting repeated at an identical ring-fault geometry every decade. This implies that magma recharges into a shallow sub-caldera chamber, which leads to ring-fault ruptures repeating at least for the decades.4. ConclusionsWe propose a physical mechanism of volcanic tsunami earthquakes by constructing their kinematic source models. A similar mechanism is also suggested for the 2017 Curtis earthquake, although we do not refer to the details here. Our model provides new and first evidences of trapdoor faulting at submarine calderas. We also demonstrate that we can study remote active submarine volcanoes using far-field observations of tsunamis and long-period seismic waves from Mw 5-6 earthquakes.