Global Mapping of an Exo-Earth Using Sparse Modeling

We develop a new retrieval scheme for obtaining two-dimensional surface maps of exoplanets from scattered light curves. In our scheme, the combination of the L1-norm and total squared variation, which is one of the techniques used in sparse modeling, is adopted to find the optimal map. We apply the new method to simulated scattered light curves of the Earth, and find that the new method provides a better spatial resolution of the reconstructed map than those using Tikhonov regularization. We also apply the new method to observed scattered light curves of the Earth obtained during the two-year Deep Space Climate Observatory/Earth Polychromatic Imaging Camera observations presented by Fan et al. The method with Tikhonov regularization enables us to resolve North America, Africa, Eurasia, and Antarctica. In addition to that, the sparse modeling identifies South America and Australia, although it fails to find Antarctica, maybe due to low observational weights on the poles. Besides, the proposed method is capable of retrieving maps from noise-injected light curves of a hypothetical Earthlike exoplanet at 5 pc with a noise level expected from coronagraphic images from a 8 m space telescope. We find that the sparse modeling resolves Australia, Afro-Eurasia, North America, and South America using 2 yr observation with a time interval of one month. Our study shows that the combination of sparse modeling and multiepoch observation with 1 day or 5 days per month can be used to identify main features of an Earth analog in future direct-imaging missions such as the Large UV/Optical/IR Surveyor

Global Mapping of Surface Composition on an Exo-Earth Using Sparse Modeling

The time series of light reflected from exoplanets by future direct imaging can provide spatial information with respect to the planetary surface. We apply sparse modeling to the retrieval method that disentangles the spatial and spectral information from multi-band reflected light curves termed as spin-orbit unmixing. We use the $\ell_1$-norm and the Total Squared Variation norm as regularization terms for the surface distribution. Applying our technique to a toy model of cloudless Earth, we show that our method can infer sparse and continuous surface distributions and also unmixed spectra without prior knowledge of the planet surface. We also apply the technique to the real Earth data as observed by DSCOVR/EPIC. We determined the representative components that can be interpreted as cloud and ocean. Additionally, we found two components that resembled the distribution of land. One of the components captures the Sahara Desert, and the other roughly corresponds to vegetation although their spectra are still contaminated by clouds. Sparse modeling significantly improves the geographic retrieval, in particular, of cloud and leads to higher resolutions for other components when compared with spin-orbit unmixing using Tikhonov regularization.Comment: 26 pages, 10 figures, accepted for publication in Ap

Modeling photometric variations due to a global inhomogeneity on an obliquely rotating star: application to lightcurves of white dwarfs

We develop a general framework to compute photometric variations induced by the oblique rotation of a star with an axisymmetric inhomogeneous surface. We apply the framework to compute lightcurves of white dwarfs adopting two simple models of their surface inhomogeneity. Depending on the surface model and the location of the observer, the resulting lightcurve exhibits a departure from a purely sinusoidal curve that are observed for a fraction of white dwarfs. As a specific example, we fit our model to the observed phase-folded lightcurve of a fast-spinning white dwarf ZTF J190132.9+145808.7 (with the rotation period of 419s). We find that the size and obliquity angle of the spot responsible for the photometric variation are \dts \approx 60^\circ and \thetaS \approx 60^\circ or $90^\circ$, respectively, implying an interesting constraint on the surface distribution of the magnetic field on white dwarfs.Comment: 25 pages, 9 figures, accepted for publication in PAS

3D Selection of 167 Substellar Companions to Nearby Stars

© 2022. The Author(s). Published by the American Astronomical Society. This is an open access article distributed under the Creative Commons Attribution License, to view a copy of the license, see: https://creativecommons.org/licenses/by/4.0/We analyze 5108 AFGKM stars with at least five high-precision radial velocity points, as well as Gaia and Hipparcos astrometric data, utilizing a novel pipeline developed in previous work. We find 914 radial velocity signals with periods longer than 1000 days. Around these signals, 167 cold giants and 68 other types of companions are identified, through combined analyses of radial velocity, astrometry, and imaging data. Without correcting for detection bias, we estimate the minimum occurrence rate of the wide-orbit brown dwarfs to be 1.3%, and find a significant brown-dwarf valley around 40 M Jup. We also find a power-law distribution in the host binary fraction beyond 3 au, similar to that found for single stars, indicating no preference of multiplicity for brown dwarfs. Our work also reveals nine substellar systems (GJ 234 B, GJ 494 B, HD 13724 b, HD 182488 b, HD 39060 b and c, HD 4113 C, HD 42581 d, HD 7449 B, and HD 984 b) that have previously been directly imaged, and many others that are observable at existing facilities. Depending on their ages, we estimate that an additional 10–57 substellar objects within our sample can be detected with current imaging facilities, extending the imaged cold (or old) giants by an order of magnitude.Peer reviewe

地域社会における観光デザインに関する実践的研究/有馬温泉及び六甲摩耶山上地区を対象として

神戸市は、有馬温泉及び六甲摩耶山上地区など観光地を有する。しかし、近年双方の観光客は減少の傾向にある。本研究では、前出地区の活性化を目的に本学学生と共に実践的なデザインを行った。また、別府温泉「混浴温泉世界」、九州地区の温泉観光地として、「由布院温泉」及び「黒川温泉」の調査を行った。研究の結果、地域社会との連携方法として、地元の観光地におけるデザインの実践が展開でき、学生たちと共同で行えることが分かった。さらに調査からも観光地におけるアート＆デザインによる活性化を目的とした実践の場があると考えられる。Kobe city has sightseeing spot such as Arima Onsen and Rokko Maya area. However, recently as for both tourists tend to decrease. In this studies, practical design made with the students for the purpose of activation in both sightseeing spots. In addition, we investigated the Beppu Onsen “Mixed Bathing World”, and “Yufuin Onsen” and “Kurokawa Onsen” in the Kyushu District.The result of research, as collaboration method of community, be able to develop the practice of the design in sightseeing spot of local, it was joint with the students and it understood that it can do. Furthermore, we thought that there are place of the practice which designates the activation with Art & Design in sightseeing spots

「学科間プロジェクト」のカリキュラム開発に関する実践的研究/「有馬温泉ゆけむり大学」を事例として

本研究では、「有馬温泉ゆけむり大学」を実践的なデザイン教育の場として研究を行った。すなわち、「学科間プロジェクト」の教育的効果を再考するために、本イベントの「Tシャツ」、「チラシ」デザイン、及び有志学生による「神戸芸工大雑貨屋さん」、「浴衣DEファッションショー」を開催した。その他イベントとして、「有馬温泉クリスマスツリープロジェクト」のワークショップ、「有馬節分会」の「チラシ」デザインを行った。また、武蔵野美術大学・群馬県立女子大学・立命館アジア太平洋大学に出向き、聞き取り調査を行った。研究の結果、「有馬温泉ゆけむり大学」に参加した学生は、他の学科及び学年を超えた交流の機会ができた。また、特に大阪音楽大学・近畿大学・武庫川女子大学の学生たち及び有馬温泉のスタッフとも交流ができたことは、大変貴重な経験となり、様々な教育効果が期待できる。したがって、「学科間プロジェクト」のカリキュラム開発のための基礎資料を得ることができた。In this studies, we studied that the "Arima Onsen Yukemuri University" was for design practical education. That is, in order to rethink the educational effect of "Interdepartmental Project", of this event "T-shirt", "Flyer" design, and by volunteer students "Kobe Design University Zakkaya san", "Yukata DE Fashion show" were held. As other events, workshop of "Arima Onsen Christmas tree project" , "Flyer" design for "Arima Setsubun E".In addition, visited to Musashino Art University, Gunma Prefectural Women\u27s University, Ritsumeikan Asia Pacific University, which were investigated.Results of the studies, students who participated in the "Arima Onsen Yukemuri University" was able opportunity of exchange beyond the school year and other departments. In addition, it becomes a very valuable experience, that the staff of Arima Onsen and students of Osaka College of Music, Kinki University, Mukogawa Women\u27s University also could exchange in particular can be expected to be teaching a variety of effects. Therefore, it was possible to obtain the basic data for curriculum development "Interdepartmental Project"

高大連携による理工学系デザイン教育カリキュラムの設計と実践/「総合的な学習の時間」のカリキュラム構築

　本研究は、高等学校学習指導要領の柱のひとつでもある「知識・技能の習得と思考力・判断力・表現力等の育成のバランスを重視」という視点に立ち、理工学分野とデザイン・芸術学分野の両側面からアプローチするデザイン教育カリキュラムを策定・実施することを目的としている。　本研究の効果として、以下の点が上げられる。① 高校施設の一貫した活用による、大学教育の体験学習を継続的に行うことができた。また、特別教室を用い、芸術系・工学系の実習制作作業を盛り込むことで、本学の学習環境を高校内でも体験的に実施することができた。② 大学生および卒業生の学習環境への取込により、高校生にとって、大学での学習をより身近に感じることのできる総合学習の時間を用意することができた。また、制作を通じた学生との高校生とのコミュニケーションによって、大学における勉学の具体的なイメージを高校生に知らせることができた。③ 高校での授業時間外において、大学の施設・設備を用いることで、制作に対するより専門的な知識・経験を高校生に提供することができ、高校生のものづくりに対する意識を高めることができた。We received the practice of the 2014 fiscal year, in the present study was to practice the following points.1) Efforts to design and practice of science and engineering-based design education curriculum, practice in order to organize the discussion and curriculum of educational theory research.2) While leveraging a comprehensive knowledge and skills, look back and decision-making, construction of design education curriculum of the method and the like of self-evaluation.3) By curriculum to approach from both sides of the science and engineering and design and art science field, enhance the ability to think from both sides of the statement. By curriculum to approach from both sides of the science and engineering and design and art science field, enhance the ability to think from both sides of the statement and sciences, depending on their own interests, their own aptitude, knowledge and skills that you gave to the body student training to be fulfill the course realization on can be expected

高大連携による理工学系デザイン教育カリキュラムの設計と実践Ⅱ／「総合的な学習の時間」のカリキュラム構築

　本研究は、高等学校学習指導要領の柱のひとつでもある「知識・技能の習得と思考力・判断力・表現力等の育成のバランスを重視」という視点に立ち、理工学分野とデザイン・芸術学分野の両側面からアプローチするデザイン教育カリキュラムを策定・実施することを目的としている。　本研究の効果として、以下の点が上げられる。① 本研究の対象となる総合的な学習において、他大学の実施する講座との横の連携を意識したドキュメンテーションを行うことで、それぞれの講座を受講する高校生に、他の講座への関心を持たせるとともに、総合的な学習全体への理解や関心を高めることができた。② 減災に関わるファッション・プロダクトデザインや、高校の周辺地域の文化・自然資源を活かした講義および実習制作に焦点を絞ることで、地域におけるデザインの役割と、大学においてデザインを学ぶ意味性を高校生に持たせることができた。③ 3 年間の継続研究によって、普通科高校におけるデザイン的指向を持つ、年間を通じた学習プログラムを実施したことにより、地域に根付き、地域の資源を活かしたデザイン教育を実施することで、総合的な学習に適した教育プログラムを構築できた。We have some knowledge as follows:1) We could raise my overall understanding and interest in learning by conducting sentences conscious of sideways collaboration with courses practiced by other universities, students taking each course will be interested in other courses.2) We were able to give high school students the role of design in the area and the meaning of learning design at university.3) Through three years of continuing research, we were able to build an educational program suitable for comprehensive learning by taking root in the community and implementing design education making use of local resources. By curriculum to approach from both sides of the science and engineering and design and art science field, enhance the ability to think from both sides of the statement and sciences, depending on their own interests, their own aptitude, knowledge and skills that you gave to the body student training to be fulfill the course realization on can be expected