Details of a Researcher - YOSHINO, Naoyuki

Papers - YOSHINO, Naoyuki

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Rethinking the Domar (<i>r-g</i>) Condition: Its Application to Greece, Japan, and China

Yoshino, N; Miyamoto, H; Terada-Hagiwara, A

ASIAN ECONOMIC PAPERS 24 ( 3 ) 53 - 66 2025.11

Joint Work, ISSN 1535-3516

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Full-field rheo-optical analysis of wormlike and networked micellar structures under uniaxial extensional flow

Masakazu Muto, Naoki Kako, Tatsuya Yoshino, Shinji Tamano

2025.07

Joint Work

The present study proposes a novel full-field extensional rheo-optical technique to investigate the relationship between the rheological properties and internal structural deformation of complex fluids under uniaxial extensional flow. Macroscopic viscoelasticity from rheological measurements and microscopic birefringence from optical measurements are integrated to evaluate the microstructural deformation and orientation of the fluids under extensional stress. The proposed technique integrates a liquid dripping method with a high-speed polarization camera to measure the extensional stress and flow birefringence simultaneously. In the liquid dripping method, temporal evolution images of the liquid filament diameter for fluids dripping from a nozzle are measured to obtain the extensional stress loading on the filament. These images are acquired using the high-speed polarization camera that captures full-field two-dimensional (2D) birefringence with high spatiotemporal resolution. Wormlike and networked micellar solutions of cetyltrimethylammonium bromide (CTAB) and sodium salicylate (NaSal) with varying concentrations of CTAB and NaSal are employed as the measurement targets. Consequently, we successfully visualized temporally developing images of the flow birefringence field of uniaxially extending micellar solutions induced by the orientation of micelles. Furthermore, the proposed technique supports investigating the conditions for establishing the stress-optical rule, which is the linear relationship between stress and birefringence. The stress-optical coefficient, which is a proportionality constant indicating the sensitivity of birefringence to stress, is analyzed from these measurements. The stress-optical coefficient under uniaxial extensional flow, obtained using the proposed technique, is confirmed to be comparable to that under shear flow.

Disambiguating Reference in Visually Grounded Dialogues through Joint Modeling of Textual and Multimodal Semantic Structures

Shun Inadumi, Nobuhiro Ueda, Koichiro Yoshino

2025.05

Joint Work

Multimodal reference resolution, including phrase grounding, aims to understand the semantic relations between mentions and real-world objects. Phrase grounding between images and their captions is a well-established task. In contrast, for real-world applications, it is essential to integrate textual and multimodal reference resolution to unravel the reference relations within dialogue, especially in handling ambiguities caused by pronouns and ellipses. This paper presents a framework that unifies textual and multimodal reference resolution by mapping mention embeddings to object embeddings and selecting mentions or objects based on their similarity. Our experiments show that learning textual reference resolution, such as coreference resolution and predicate-argument structure analysis, positively affects performance in multimodal reference resolution. In particular, our model with coreference resolution performs better in pronoun phrase grounding than representative models for this task, MDETR and GLIP. Our qualitative analysis demonstrates that incorporating textual reference relations strengthens the confidence scores between mentions, including pronouns and predicates, and objects, which can reduce the ambiguities that arise in visually grounded dialogues.

CRYPTOCURRENCIES, MONEY DEMAND, AND MONETARY POLICY

Mumtaz M.Z., Smith Z.A., Yoshino N.

Buletin Ekonomi Moneter Dan Perbankan Monetary and Banking Economics Bulletin 28 ( 2 ) 293 - 312 2025

Joint Work, ISSN 14108046

This study examines the nexus between money demand and cryptocurrencies by estimating two simultaneous equations using Divisia indices as a proxy for money demand and volume traded for cryptocurrencies. The study examines the linkage between cryptocurrencies and money demand and their potential influence over monetary policy actions. It finds that the volume of cryptocurrencies traded negatively influences money demand. Moreover, we see a positive association between money demand and cryptocurrencies, implying that as the demand for money increases, the demand for cryptocurrencies increases. Further, we examine the determinates of cryptocurrencies and report that the return of cryptocurrencies, the financial development index, GDP, inflation, and stock market indices are significant predictors of the demand for cryptocurrencies.

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CRYPTOCURRENCIES, MONEY DEMAND, AND MONETARY POLICY

Mumtaz M.Z., Smith Z.A., Yoshino N.

Buletin Ekonomi Moneter Dan Perbankan Monetary and Banking Economics Bulletin 28 ( 2 ) 293 - 312 2025

Joint Work, ISSN 14108046

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Simulation Tool Development and Sensitivity Analysis of 160Gd Double Beta Decay Search by the PIKACHU Project

Takumi Omori, Takashi Iida, Nobuo Hinohara, Kotaro Takahashi, Ken-Ichi Fushimi, Azusa Gando, Keishi Hosokawa, Shotaro Ishidate, Motonao Ishigami, Kei Kamada, Keita Mizukoshi, Yasuhiro Shoji, Hisanori Suzuki, Masao Yoshino

2024.12

Joint Work

Neutrinoless double beta decay (0v2b) has been investigated as a physical process that can provide evidence for the Majorana nature of neutrinos. The theoretical predictions of the 0v2b rate are subject to significant uncertainty, primarily due to nuclear matrix elements (NME). To reduce this uncertainty, experimental measurements of the half-lives of two-neutrino double beta decay (2v2b) in various nuclei are essential as a benchmark for NME calculations. The PIKACHU (Pure Inorganic scintillator experiment in KAmioka for CHallenging Underground sciences) project searches for the previously unobserved 2v2b decay of 160Gd, employing Ce-doped Gd3Ga3Al2O12 (GAGG) single crystals. In the Phase 1 experiment, we aim to improve the current lower limit on the 2v2b half-life of 160Gd by a prior study using a Ce-doped Gd2SiO5 (GSO) crystal. Ultimately, in Phase 2, the project seeks to achieve a sensitivity surpassing the theoretical prediction of 7.4 x 10^20 years, enabling the potential discovery of the 160Gd 2v2b decay. In this paper, we describe the development of background models based on GEANT4 simulations. The modeled backgrounds are contributions from uranium and thorium decay chains, 40K present in GAGG, and 40K gamma-rays from outside of GAGG. Additionally, we developed models for both 2v2b and 0v2b decay by implementing the theoretical kinematics of two-electron emission in double beta decay in the GEANT4 simulation. As a result, our background models successfully reproduced the measured background spectrum through fitting. By generating pseudo background spectra expected in Phase 1 and analyzing them with the combined background and 2v2b models, we evaluated the 2v2b sensitivity of Phase 1 to be 2.78 x 10^19 years (90% C.L.). This paper presents the development of these simulation models and the expected sensitivities for both Phase 1 and Phase 2 based on the pseudo data analyses.

Development and performance evaluation of a thin GAGG:Ce scintillator plate for high resolution synchrotron radiation X-ray imaging

Masao Yoshino, Seiichi Yamamoto, Kohei Nakanishi, Katsunori Yogo, Kei Kamada, Nanase Koshikawa, Jun Kataoka, Akira Yoshikawa

2024.10

Joint Work

Scintillator-based X-ray imaging detectors are pivotal in numerous scientific and practical domains, including medical imaging, and security monitoring. Recent advancements have spurred interest in 4D X-ray imaging using synchrotron radiation, necessitating higher temporal resolutions. Consequently, this places stringent demands on X-ray detector technology, especially when X-ray energy exceeds 20 keV. The selection of a suitable scintillator material is crucial for achieving optimal timing resolution, yet it poses a significant challenge in dynamic X-ray imaging. This study delves into the optimization of scintillator properties and their impact on spatial resolution and light output, elucidating the performance of Ce-doped Gd3Ga3Al2O12 (GAGG:Ce) scintillators for X-ray imaging applications. We developed a micro X-ray imaging detector using a 100 $μ$m-thick GAGG:Ce scintillator plate and conducted X-ray imaging tests at the Aichi SR facility. The results demonstrated that the resolution, quantified as the chart slit width at a contrast transfer function (CTF) value of 10%, reached 2 - 3 $μ$m with a 4x lens, 0.52 $μ$m $\pm$ 0.03 $μ$m with a 20x lens, and 0.42 $μ$m $\pm$ 0.01 $μ$m with a 40x lens. Although the results of this study did not achieve a spatial resolution nearing the effective pixel size of the 40x lens, the text also elucidates the underlying reasons for this limitation. Furthermore, we compared the X-ray sensitivity of our GAGG:Ce scintillator plate with that of a commercial LuAG:Ce scintillator, revealing an approximately 1.5-fold increase in light output. As a demonstration, transmission images of dried small fish were captured using the GAGG:Ce scintillator plate and the developed X-ray imaging system. These findings highlight the potential of the X-ray imaging detector devised in this study for future generations of X-ray imaging applications.

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LLM-jp: A Cross-organizational Project for the Research and Development of Fully Open Japanese LLMs

LLM-jp, :, Akiko Aizawa, Eiji Aramaki, Bowen Chen, Fei Cheng, Hiroyuki Deguchi, Rintaro Enomoto, Kazuki Fujii, Kensuke Fukumoto, Takuya Fukushima, Namgi Han, Yuto Harada, Chikara Hashimoto, Tatsuya Hiraoka, Shohei Hisada, Sosuke Hosokawa, Lu Jie, Keisuke Kamata, Teruhito Kanazawa, Hiroki Kanezashi, Hiroshi Kataoka, Satoru Katsumata, Daisuke Kawahara, Seiya Kawano, Atsushi Keyaki, Keisuke Kiryu, Hirokazu Kiyomaru, Takashi Kodama, Takahiro Kubo, Yohei Kuga, Ryoma Kumon, Shuhei Kurita, Sadao Kurohashi, Conglong Li, Taiki Maekawa, Hiroshi Matsuda, Yusuke Miyao, Kentaro Mizuki, Sakae Mizuki, Yugo Murawaki, Akim Mousterou, Ryo Nakamura, Taishi Nakamura, Kouta Nakayama, Tomoka Nakazato, Takuro Niitsuma, Jiro Nishitoba, Yusuke Oda, Hayato Ogawa, Takumi Okamoto, Naoaki Okazaki, Yohei Oseki, Shintaro Ozaki, Koki Ryu, Rafal Rzepka, Keisuke Sakaguchi, Shota Sasaki, Satoshi Sekine, Kohei Suda, Saku Sugawara, Issa Sugiura, Hiroaki Sugiyama, Hisami Suzuki, Jun Suzuki, Toyotaro Suzumura, Kensuke Tachibana, Yu Takagi, Kyosuke Takami, Koichi Takeda, Masashi Takeshita, Masahiro Tanaka, Kenjiro Taura, Arseny Tolmachev, Nobuhiro Ueda, Zhen Wan, Shuntaro Yada, Sakiko Yahata, Yuya Yamamoto, Yusuke Yamauchi, Hitomi Yanaka, Rio Yokota, Koichiro Yoshino

2024.07

Joint Work

This paper introduces LLM-jp, a cross-organizational project for the research and development of Japanese large language models (LLMs). LLM-jp aims to develop open-source and strong Japanese LLMs, and as of this writing, more than 1,500 participants from academia and industry are working together for this purpose. This paper presents the background of the establishment of LLM-jp, summaries of its activities, and technical reports on the LLMs developed by LLM-jp. For the latest activities, visit https://llm-jp.nii.ac.jp/en/.

J-CRe3: A Japanese Conversation Dataset for Real-world Reference Resolution

Nobuhiro Ueda, Hideko Habe, Yoko Matsui, Akishige Yuguchi, Seiya Kawano, Yasutomo Kawanishi, Sadao Kurohashi, Koichiro Yoshino

2024.03

Joint Work

Understanding expressions that refer to the physical world is crucial for such human-assisting systems in the real world, as robots that must perform actions that are expected by users. In real-world reference resolution, a system must ground the verbal information that appears in user interactions to the visual information observed in egocentric views. To this end, we propose a multimodal reference resolution task and construct a Japanese Conversation dataset for Real-world Reference Resolution (J-CRe3). Our dataset contains egocentric video and dialogue audio of real-world conversations between two people acting as a master and an assistant robot at home. The dataset is annotated with crossmodal tags between phrases in the utterances and the object bounding boxes in the video frames. These tags include indirect reference relations, such as predicate-argument structures and bridging references as well as direct reference relations. We also constructed an experimental model and clarified the challenges in multimodal reference resolution tasks.

Enhancing private infrastructure financing through capturing spillover effect: Conceptual development and an empirical case study of Vietnam’s expressways

Yoshino N., Abe M., Truong H.T.

Journal of Infrastructure, Policy and Development (Journal of Infrastructure, Policy and Development) 8 ( 5 ) 2024

Joint Work, ISSN 25727923

While infrastructure provides necessary public services and is vital for the socio-economic development of a nation, public funds alone cannot finance all infrastructure needs in society, especially after the COVID-19 pandemic, where many countries are facing budget deficits. Although private financing schemes, such as public-private partnerships (PPPs) and land value capture, have been considered intensively, they have yet to produce adequate private capital flows to infrastructure projects due to a lack of incentives for private investors. Against the background, this paper proposes a new financing mechanism in which governments might divert some of the increased tax revenue from the spillover effects of newly constructed infrastructures to fund the private sector through grants or subsidies. The empirical work in Vietnam shows a significant increase in tax revenues after completing two expressways, supporting our idea about spillover effects, which includes small-and medium-sized enterprise (SME) development. This study’s results suggest that spillover effects can bring new opportunities for governments and multilateral development banks (MDBs) to implement infrastructure projects with greater private sector involvement in the region. It also proposes some financial schemes, such as land capture and financing for business startups, including SMEs, to enhance the spillover effects of infrastructure.

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Comparison of various fiscal policies in the face of different demographic stages

Naoyuki Yoshino, Keigo Kameda, Hiroaki Miyamoto, Zhenkun Lu

Singapore Economic Review (Singapore Economic Review) 69 ( 4 ) 1473 - 1497 2024

Joint Work, ISSN 02175908

This study examines the impact of aging on the effectiveness of various fiscal expenditures, including government consumption, one-time government transfers to households, public investment and R&D spending, using a dynamic stochastic general equilibrium model. Our findings reveal that (1) Aging enhances the effects of the transfer on augmenting GDP. (2) Regardless of aging, R&D expenditure consistently stands out over all time spans, with younger society benefiting more. (3) Public investment ranks second among for different fiscal policies in the long run, while shows bigger impact in younger society. (4) One-time transfer has only a temporary effect and is the least effective in boosting GDP in both young and old societies. (5) Multipliers for public investment and R&D expenditure increase with the accumulation of public capital and TFP. Their multiplier of young society is larger than old society because impact on consumption is much more effective.

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コロナ禍の下での地域金融市場：集中度、貸出・預金を通じた地域間資金循環、信用保証付き貸出

植杉威一郎, 平賀一希, 眞鍋雅史, 吉野直行

FSA Instiitute Diiscussiion Paper Seriies DP 2024-2 1 - 28 2024

Joint Work

CiNii Research

Diversified ESG Evaluation by Rating Agencies and Net Carbon Tax to Regain Optimal Portfolio Allocation

Naoyuki Yoshino, Tomonori Yuyama, Farhad Taghizadeh-Hesary

Asian Economic Papers (Asian Economic Papers) 22 ( 3 ) 81 - 96 2023.09

Joint Work, ISSN 15353516

Environmental, Society, and Governance (ESG) investments have become increasingly popular in recent years, and, at the same time, many rating agencies provide ESG scores for each company. This means that the ESG investment model may have moved from the traditional two-factor model of risk-return to a three-factor model adding an ESG component to it. This paper highlights the potential for distor tion of asset allocation through the shift from traditional risk-return considerations to ESG score considerations. This is equally true for green bonds, resulting in the potential for asset allocation to be distor ted by green bond criteria. Fur thermore, we show that imposing a net carbon tax on greenhouse gas (GHG) emissions is a measure to correct this distor tion in asset allocation and make asset allocation more risk-return based, in addressing global environmental issues.

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Uniform hyperbolicity of a class of scattering maps

Hajime Yoshino, Normann Mertig, Akira Shudo

2023.08

Joint Work

In recent years fractal Weyl laws and related quantum eigenfunction hypothesis have been studied in a plethora of numerical model systems, called quantum maps. In some models studied there one can easily prove uniform hyperbolicity. Yet, a numerically sound method for computing quantum resonance states, did not exist. To address this challenge, we recently introduced a new class of quantum maps. For these quantum maps, we showed that, quantum resonance states can numerically be computed using theoretically grounded methods such as complex scaling or weak absorbing potentials. However, proving uniform hyperbolicty for this class of quantum maps was not straight forward. Going beyond that work this article generalizes the class of scattering maps and provides mathematical proofs for their uniform hyperbolicity. In particular, we show that the suggested class of two-dimensional symplectic scattering maps satisfies the topological horseshoe condition and uniform hyperbolicity. In order to prove these properties, we follow the procedure developed in the paper by Devaney and Nitecki. Specifically, uniform hyperbolicity is shown by identifying a proper region in which the non-wandering set satisfies a sufficient condition to have the so-called sector bundle or cone field. Since no quantum map is known where both a proof of uniform hyperbolicity and a methodologically sound method for numerically computing quantum resonance states exist simultaneously, the present result should be valuable to further test fractal Weyl laws and related topics such as chaotic eigenfunction hypothesis.

Financial literacy, behavioral traits, and ePayment adoption and usage in Japan

Trinh Quang Long, Peter J. Morgan, Naoyuki Yoshino

Financial Innovation (Financial Innovation) 9 ( 1 ) 101 2023.06

Joint Work

This study investigates how financial literacy and behavioral traits affect the adoption of electronic payment (ePayment) services in Japan. We construct a financial literacy index using a representative sample of 25,000 individuals from the Bank of Japan’s 2019 Financial Literacy Survey. We then analyze the relationship between this index and the extensive and intensive usage of two types of payment services: electronic money (e-money) and mobile payment apps. Using an instrumental variable approach, we find that higher financial literacy is positively associated with a higher likelihood of adopting ePayment services. The empirical results suggest that individuals with higher financial literacy use payment services more frequently. We also find that risk-averse people are less likely to adopt and use ePayment services, whereas people with herd behavior tend to adopt and use ePayment services more. Our empirical results also suggest that the effects of financial literacy on the adoption and use of ePayment differ among people with different behavioral traits.

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Sustainable Financing Strategies for the SMEs: Two Alternative Models

Monzur Hossain, Naoyuki Yoshino, Kenmei Tsubota

Sustainability (Switzerland) (Sustainability (Switzerland)) 15 ( 11 ) 2023.06

Joint Work, ISSN 2071-1050

A sustainable financing strategy for SMEs should aim to enhance a low-cost collateral-free supply of loans to SMEs with good track records of repayments to banks. In this paper, we suggest two alternative financing models for SMEs that address certain borrowing constraints of SMEs. First, the model incorporates institutional mechanisms involving the government, banks, and SMEs. The strategy employs a two-pronged approach: (i) the government enhances the supply of loanable funds to banks, and (ii) identifies good SME borrowers through skills development programs and introduces them to banks. This model will reduce default risk and allow banks to offer lower-interest and collateral-free credit to SMEs, thereby improving their access to finance and performance. Second, the model could be extended to accommodate digital finance using a data-driven credit risk score of the borrowers to reduce banks’ default risks and transaction costs with or without government funds. The proposed model could resolve the moral hazard and selection bias problems. Our proposed models are based on a public-private partnership approach and therefore could solve certain borrowing constraints of SMEs. Our empirical results support the model outcomes and therefore are consistent with the predictions of our theoretical models.

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SMEs and carbon neutrality in ASEAN: the need to revisit sustainability policies

Naoyuki Yoshino, Ehsan Rasoulinezhad, Han Phoumin, Farhad Taghizadeh-Hesary

Economic Research-Ekonomska Istrazivanja (Economic Research-Ekonomska Istrazivanja) 36 ( 2 ) 2023

Joint Work, ISSN 1331677X

Most rules and regulations for protecting the environment and reducing greenhouse gas emissions target large enterprises. Although small and medium-sized enterprises (SMEs) have major shares in most Asian economies, they remain outside the purview of most environmental rules and regulations. The primary purpose of this study is to assess the association between SMEs’ activities and carbon emissions in the Association of Southeast Asian Nations (ASEAN) countries from 2010 to 2020. To this end, a fully modified ordinary least squares (FMOLS) model was developed. The results show that SMEs’ activities do not align with environmental protection goals and sustainable development, as the estimation results revealed their significant contributions to CO2 emissions. Other practical implications of this study for carbon-neutral SMEs are introducing green finance policies, revisiting the environmental and carbon reduction rules and regulations that cover SMEs, and changing banks’ lending mechanisms based on SMEs’ green economic performance.

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Aftermarket performance of green IPOs and portfolio allocation

Mumtaz Muhammad Zubair, Yoshino Naoyuki

GREEN FINANCE (Green Finance) 5 ( 3 ) 321 - 342 2023

Joint Work, ISSN 2643-1092

This study examines the aftermarket performance of high-green and low-green IPO and how green IPOs can optimize portfolio allocation. We assume the higher level of greenness increases investors’ participation in IPOs. To this end, we develop the utility function and determine that investors prefer to participate in new issues when firms account for greenness measures. This study proposes the global aspects of green measure: the desired level of greenness a firm maintains. We find that IPOs in our sample are far below the global standards of greenness. This evidence suggests they must adopt the necessary actions to make the environment green. Another significant contribution of this study is to measure the performance of high and low-green IPOs in short-and long-run horizons. This study reveals that high-green IPOs are less underpriced. This study estimates the effect of greenness on initial returns and finds an inverse relationship suggesting that high-green IPOs are less underpriced due to lower risk associated with new issues. In terms of measuring longer-term performance, this study determines that high-green IPOs underperform less than low-green IPOs.

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コロナ後を見据えた財政・金融政策

吉野直行, 岩田一政, 清水順子, 松元崇, 井堀利宏

Trend in Modern Economics (Japanese Economic Association) 2023 ( 0 ) 239 - 293 2023

Joint Work

Measuring Concentration in the Japanese Loan and Deposit Markets

Iichiro Uesugi, Kazuki Hiraga, Masashi Manabe, Naoyuki Yoshino

Japan and the World Economy (Elsevier BV) 63 101148 - 101148 2022.09

Joint Work, Accepted, ISSN 09221425

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