• Title/Summary/Keyword: Hokkaido University

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Polarimetric research on S- and Q-type Near-Earth Asteroids

  • Geem, Jooyeon;Ishiguro, Masateru;Bach, Yoonsoo P.;Kuroda, Daisuke;Naito, Hiroyuki;Kim, Yoonyoung;Kwon, Yuna G.;Imai, Masataka;Kuramoto, Kiyoshi;Watanabe, Makoto;Okazaki, Ryo
    • The Bulletin of The Korean Astronomical Society
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    • v.43 no.1
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    • pp.51.2-51.2
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    • 2018
  • Polarimetry is a powerful technique to investigate the physical properties of surface materials on airless bodies in the solar system. It is known that the degree of linear polarization changes as a function of the phase angle (the angle between Sun-target-Observer). Especially, the dependency of the polarization degree at large phase angle allows us to obtain information related to the particle size and porosity, which is difficult to be determined via other observation techniques (i.e., photometry and spectroscopy). However, despite the advantage, only a few asteroids were observed with polarimetric devices at large phase angles. Here, we present our new polarimetric research of Near-Earth Asteroids (NEAs) observed at the large phase angles. Among the NEAs, we focus on S- and Q-type asteroids, which include: (331471) 1984 QY1, (90075) 2002 VU94, and (66391) 1999 KW4. The observation was conducted using the Pirka 1.6-m Telescope at the Nayoro Observatory of Hokkaido University at the phase angles ${\alpha}{\sim}100degree$, which provides us the maximum polarization degrees of these objects. Considering the observational results together with two objects ((1566) Icarus and (4179) Toutatis) in reference papers [1], [2], we will discuss the implication of the regolith size on their surfaces.

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Growth Factors and Policy Implications of Hokkaido University Research & Business Park in Japan (일본 홋카이도대학 리서치 & 비즈니스파크의 성장요인과 정책적 시사점)

  • Jang, Hoo-Eun
    • Journal of the Economic Geographical Society of Korea
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    • v.25 no.3
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    • pp.339-356
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    • 2022
  • This study focuses on Hokkaido University Research & Business Park in Japan as an example of establishing a regional innovation ecosystem on campus based on the outstanding research and university-industry collaboration capabilities of local universities in non-metropolitan areas with weak foundations for start-ups and corporate growth. Hokkaido University Research & Business Park established a mid-to long-term plan using the idle sites on campus, and was developed through a gradual development process since 2003. The promotion of university-industry collaboration was pursued through an industrial-based approach of establishing a bio-industry cluster considering the characterization of local universities and the foundation of local industries. It also provides various corporate support services through cooperative governance between local industry, universities, research institutes and the government. This strategy for creating Hokkaido University Research & Business Park provides important policy implications for various policies and projects that promote regional development by utilizing university campuses like the campus innovation park project.

Molecular Detection of Verotoxigenic Escherichia coli (VTEC) from Animal Feces for Screening VTEC-shedders

  • Kobayashi, Y.;Sato, M.;Taguchi, H.;Koike, S.;Nakatsuji, H.;Tanaka, K.
    • Asian-Australasian Journal of Animal Sciences
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    • v.17 no.3
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    • pp.423-427
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    • 2004
  • Seventy-six animals including cattle, sheep, horses, 6 species of zoo animals were employed for collection of fresh feces in order to detect verotoxigenic Esherichia coli (VTEC) by safe, quick and sensitive PCR-based molecular methods. Bacterial cell disruption with bead-beating followed by bacterial DNA purification with hydroxyapatide chromatography and gel filtration allowed DNA preparation from animal feces with high recovery and purity. A mountain goat was firstly shown by PCR and sequencing to shed verotoxin 2 gene (vt2) that was used to generate vt2 probe and second primer set for nested PCR to attempt more sensitive detection. Most sensitive nested PCR revealed that 45% of tested cattle and 47% of tested zoo animals were VTEC-positive, while least sensitive normal PCR detected VTEC from none of these animals except a mountain goat. Moderately sensitive detection by PCR in combination with hybridization suggested that the VTEC density varied between the VTEC-positive cattle.

Biodesulfurization of Dibenzothiophene and Its Derivatives Using Resting and Immobilized Cells of Sphingomonas subarctica T7b

  • Gunam, Ida Bagus Wayan;Yamamura, Kenta;Sujaya, I. Nengah;Antara, Nyoman Semadi;Aryanta, Wayan Redi;Tanaka, Michiko;Tomita, Fusao;Sone, Teruo;Asano, Kozo
    • Journal of Microbiology and Biotechnology
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    • v.23 no.4
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    • pp.473-482
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    • 2013
  • The desulfurization ability of Sphingomonas subarctica T7b was evaluated using resting and immobilized cells with dibenzothiophene (DBT), alkyl DBTs, and commercial light gas oil (LGO) as the substrates. The resting cells of S. subarctica T7b degraded 239.2 mg of the initial 250 mg of DBT/l (1.36 mM) within 24 h at $27^{\circ}C$, while 127.5 mg of 2-hydroxybiphenyl (2-HBP)/l (0.75 mM) was formed, representing a 55% conversion of the DBT. The DBT desulfurization activity was significantly affected by the aqueous-to-oil phase ratio. In addition, the resting cells of S. subarctica T7b were able to desulfurize alkyl DBTs with long alkyl chains, although the desulfurization rate decreased with an increase in the total carbon number of the alkylated DBTs. LGO with a total sulfur content of 280 mg/l was desulfurized to 152 mg/l after 24 h of reaction. Cells immobilized by entrapment with polyvinyl alcohol (PVA) exhibited a high DBT desulfurization activity, including repeated use for more than 8 batch cycles without loss of biodesulfurization activity. The stability of the immobilized cells was better than that of the resting cells at different initial pHs, higher temperatures, and for DBT biodesulfurization in successive degradation cycles. The immobilized cells were also easily separated from the oil and water phases, giving this method great potential for oil biodesulfurization.

A Phytosociological Study of Hokkaido Vegetation, Japan (북해도 식생에 대한 식물사회학적 고찰)

  • Kim, Jong-Won
    • The Korean Journal of Ecology
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    • v.12 no.2
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    • pp.109-122
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    • 1989
  • The vegetation and landscape of Hokkaido were phytosociologically referred. The region of F a g e t e a c r e n a t a e on Hokkaido is divided into two types of deciduous broad-leaved forest: the oak (Quercus mongolica var. grosseserrata) forests mixed with conifers (mainly Abies sachalinensis) and the beech (Fagus crenata) forests of northernmost distribution in far-east Asia. The oak forests, which is dominated by Quercus mongolica var. grosseserrata in Japanse islands, seem to be developed from different climatic and edaphic conditions, especially in the amount and sharing pattern of precipitation in a year, and weak acid brown forest soil, volcanic ash soil and sandy soil. On the all-inclusive phytogeographical view-point, Hokkaido is situated at northernmost region of F a g e t e a c r e n a t a e (cool-temperate zone)neighboring with subarctic and subalpine vegetation, vegetation, but the evergreen broad-leaved forest (C a m e l l i e t e a j a p o n i c a e, warm-temperate zone) is abscent.

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Effect of Asp193 on Proton Affinity of the Schiff Base in pharaonis phoborhodopsin

  • Iwamoto, Masayuki;Furutani, Yuji;Sudo, Yuki;Shimono, Kazumi;Kandori, Hideki;Kamo, Naoki
    • Journal of Photoscience
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    • v.9 no.2
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    • pp.305-307
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    • 2002
  • Spectroscopic titration of D 193N and D 193E mutants of pharaonis phoborhodopsin (ppR) were performed to evaluate the pK$_{a}$ of the Schiff base Asp 193 corresponds to Glu204 of bacteriorhodopsin (bR). The pK$_{a}$ of the Schiff base (SBH$^{+}$) of D193N was 10.1~10.0 (at XH$^{+}$) and 11.4~11.6 (at X) depending on the protonation state of a certain residue (designated by X) and independent on CI$^{[-10]}$ , while those of the wild-type and D193E were> 12. pK$_{a}$ of XH$^{+}$ were; 11.8~11.2 at the state of SB, 10.5 at SBH$^{+}$ state in the presence of CI$^{[-10]}$ , and 9.6 at SBH$^{+}$ without CI$^{[-10]}$ These imply the presence of a long-range interaction in the extracellular channel.r channel.

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Co-evolutionary Design of Team Level Play in Soccer Server

  • Masatoshi Hiramoto;Hidenori Kawamura;Masahito Yamamoto;Keiji Suzuki;Azuma Ohuchi
    • Proceedings of the IEEK Conference
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    • 2000.07b
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    • pp.727-730
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    • 2000
  • Recently, RoboCup soccer simulation has been regarded as a good benchmark problem for multiagent researches. Soccer agents have to make decision based on visual and auditory information, which are sent from the soccer server. In order to develop a strong team, we have to design decision-making process of each player agent. However, it is very difficult for us to design the decision-making processes in detail, because we don't know what actions of each player are effective for the team. In this paper, we attempt to apply co-evolutionary method, which is one type of analogies of evolution, to improve the team play. Agents have hand coded basic skills, which include dribble, shoot, pass etc. Agents already can play autonomously and independently. Individual agent skills are characterized by some parameters. By coevolving teams with these parameters, we obtained relatively interesting teams, in which players behave cooperatively in order to win the soccer game. From some experiments, we discuss what teams are evolved.

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Classification of the blood groups in Cheju native horses by the antiserum of isoimmunization (동종면역항혈청(同種免疫抗血淸)에 의한 제주마(濟州馬) 혈액형(血液型) 분류(分類))

  • Han, Bang-keun;Chang, Duk-gi;Kim, Sang-keun;Matsumoto, Hiroshi
    • Korean Journal of Veterinary Research
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    • v.32 no.3
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    • pp.451-456
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    • 1992
  • Seventeen antiserum identified by stormont method were used for investigation of appearance type of red blood cell in Cheju horse. Phenotype $A_1$, A', Z, $ZZ_2$, C, K, $P_1$, Q, R, S, $U_2$, X and $N_1$ were classified by Hemolytic reaction and agglutination in $E_2$, H, J and $T_1$, Hokkaido horse and Thoroughbred horse were compared with the type of red blood cell. The results obtained are as follows ; 1. According to the appearance frequency of red blood cell the phenotypes could be classified by 6 groups among horses tested; I group : C, $A_1$, $ZZ_2$, $E_2$, S, Q, II : $P_1$, $U_2$, X, III : A', R, IV : $T_1$, K, V : H, J, VI, $N_1$, Z. 2. In group I the type of C, $A_1$ and $ZZ_2$ showed the Similar frequency among horses but the type of $E_2$, S and Q was lower in Cheju horse than Hokkaido and Thoroughbred horse. 3. In group II there was no differences in the type of $P_1$ and among three species, but Thoroughbred horse was lowest as 11.2 percent than Cheju and Hokkaido horse. 4. The type of $U_2$ and X were highest in Cheju and Hokkaido horse but lowest in Thoroughbred horse. 5. The type of A' and R observed higher appearance frequency in Hoklcaido horse but in the Thoroughbred and Cheju horse appearance ratio were Strikingly lowered. 6. The type of $T_1$ and K was shown higher appearance frequency in Cheju and Thoroughbred horse similarily but lowered in Hokkaido horse. 7. In group V the type of H and J showed similarily as 30 to 40 percent in Cheju and Thoroughbred but no observation in Hokkaido horse. 8. The type of $N_1$ and Z which are group VI was great difference between Cheju and Hokkaido horse but higher in Hokkaido than Cheju horse while there was no observation in thoroughbred horse.

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Tectonic Features of a Triple-Plate Junction in Hokkaido Using Local Seismic Tomography

  • Kim, So-Gu;Bae, Hyung-Sub;Pak, Sang-Pyo
    • Proceedings of the KSEG Conference
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    • 2005.04a
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    • pp.101-106
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    • 2005
  • The three-dimensional Tomography developed by Kim and Bae(2004) was applied to 64,024 P and 64,618 S wave arrival times observed at 238 seismic stations for 4050 local earthquakes in the depth range from 0 to 300 km in and around Hokkaido, Japan. High and low velocity zones for Vp/Vs were clearly imaged in and around Hokkaido. The upper seismic planes of the double seismic zone (DSZ) were found in the subducted Pacific Plate beneath Hokkaido at depth of 40- 80 km, which produced high seismicity around Hokkaido. The findings of high Vp/Vs anomalies beneath the Moho discontinuity supports an evidence of a surface triple-collision hypothesis prepared by Moriya(1994) that the Kuril Arc(Okhotsk Plate or North American Plate) is colliding against the NE Japanese Arc(Amurian Plate or Eurasian Plate), along and beneath the Hidaka Mountain Range, and at the same time the Pacific Plate is subducting into these two plates, making an equilibrium of tectonic forces along the Hikada Mountain Range (HMR) corner and the central tectonic axis(142 ~ 143E) in Hokkaido. The low Vp and Vs were also found in east and west along the central tectonic axis in which the focal mechanism represents the extensional forces. These phenomena are also consistent with low Bouguer gravity anomalies in this region. It is understood why most of great earthquakes occurred outside Hokkaido where the balance of tectonic forces are breaking from the triple junction of three tectonic forces in Hokkaido.

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