T Kato

Nagoya University, Nagoya, Aichi, Japan

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Publications (377)1143.38 Total impact

  • T. Kato, K. Kawai, Y. Suzuoki
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    ABSTRACT: An electric power system containing high penetration photovoltaic power generation system (PVS) should employ a highly accurate day-ahead forecast method of aggregated power output of PVS in the generation scheduling so as to realize the economic load dispatching. Considering the load-following capability of utility generators, however, small forecast error is not so influential, while large forecast error should be avoided. By using a simplified unit commitment model, this study evaluates the forecast accuracy of aggregated PVS power output by means of the amount of shortage or surplus of power supply in the electric power system. As a result, the shortage occurs occasionally, requiring the increase in the operating reserve. The surplus occasionally occurs in spring even without the forecast error. Avoiding the large forecast error contributes to the decrease in the operating-reserve of utility generators as well as the suppressed PVS power output, even though the average forecast accuracy is not improved so much.
    Power and Energy Society General Meeting (PES), 2013 IEEE; 01/2013
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    ABSTRACT: We observed the distribution of the superconducting gap in Bi2Sr2-xLaxCuO6+δ (Bi2201-La) by scanning tunneling spectroscopy at x = 0.2 (over doped), 0.4 (optimally doped) and 0.6 (under doped). The superconducting gap was spatially distributed in all samples. As the carrier concentration is reduced, the distribution became much broader and the mean value of superconducting gap, Δmean increased. We found that the distribution and Δmean in Bi2201-La grew more rapidly than in Bi2Sr2CaCu2O8+δ with decreasing the carrier concentration.
    International Journal of Modern Physics B 01/2012; 21(18n19). · 0.46 Impact Factor
  • H.sakata, K.hosokawa, T.kato
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    ABSTRACT: We measured the dielectric dispersion in multi-ferroic TbMnO3. We observed two kinds of the dielectric dispersions. One dispersion showed the monotonous temperature dependence of the relaxation frequency across the ferroelectric transition temperature, Tc. This dispersion is thought to be originated from the localized charge. The other dispersion existed only near the Tc, attributed to the ferroelectric transition. We found the former dispersion enhanced its strength near Tc. This indicates that the localized charge couples with the electric moment which orders in the ferroelectric phase.
    International Journal of Modern Physics B 01/2012; 21(18n19). · 0.46 Impact Factor
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    ABSTRACT: The spatial evolution of the background conductance in the tunneling spectra was investigated with low-temperature scanning tunneling spectroscopy on a slightly overdoped Bi2Sr1.74La0.26CuO6+δ single crystal at 4.2 K. The asymmetry in the background conductance between positive and negative biases strongly correlates with the local energy gap, which shows the inhomogeneous spatial variation: the tunneling spectra become more asymmetric in the regions where the spectra exhibit larger gap value.
    International Journal of Modern Physics B 01/2012; 21(18n19). · 0.46 Impact Factor
  • T. Kato, Y. Suzuoki
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    ABSTRACT: The high penetration photovoltaic power generation systems (PVS) may cause the voltage rise of a power distribution system. As one of the measures, we focus on the daytime operation of heat pump water heater (HPWH). This study introduces the brief idea for scheduling the daytime operation so that the total electricity demand change of a number of HP follows the insolation change in a day. Then, this study demonstrates the effect of daytime operation using the electricity and hot-water demand observed in 10 households for a year. As the result, when the daytime operation is applied to HPWH in a household with PVS, the voltage rise can be mitigated without causing the under voltage condition due to the unnecessary daytime operation.
    Engineering and Technology (S-CET), 2012 Spring Congress on; 01/2012
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    ABSTRACT: We investigated the influence of AC voltage prestressing on the electrical-tree inception voltage in LDPE. When AC voltage prestress was not imposed, the impulse-tree inception voltage increased with the size of water tree due to the electrical field relaxation. On the other hand, when AC voltage prestress was imposed, the impulse-tree inception voltage did not change with the water-tree size and was lower than that without AC voltage prestressing. The FTIR absorption measurements showed several absorptions between 650 and 1500 cm-1, which did not exist in the sample without AC voltage prestressing. Besides, the TEM observation revealed that the AC voltage prestressing increased the density and size of micro voids and some of them were aligned in the direction of applied electric field. These results suggest that AC voltage prestressing causes structural change in the water tree and enhances material degradation, leading to lower tree-inception voltage.
    Electrical Insulation and Dielectric Phenomena (CEIDP), 2012 Annual Report Conference on; 01/2012
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    ABSTRACT: High penetration photovoltaic power generation system (PVS) would cause some negative impacts on the stable operation of electric power system. On the other hand, when PVSs are widely dispersed, the total power output fluctuation would be smoothed. In order to evaluate the spatial average insolation fluctuation by using the insolation data observed at the limited number of points, we have developed the method to take the smoothing-effect around the observation point into account. Then, by using the insolation data observed at 61 points in the Chubu region in Japan, this study statistically evaluated the long-cycle fluctuation of the spatial average insolation. As the results, the absolute value of the maximum fluctuation width (MFW) of ensemble average insolation calculated with 120 min width window ranges mainly between 200 and 300 W/m2, while it is larger than 400 W/m2 in 6 days (1.7%). The results suggest that the reliable forecast method of spatial average insolation is needed to mitigate the impact of total power output change due to the insolation change of 400 W/m2 in 120 min.
    Power and Energy Society General Meeting, 2012 IEEE; 01/2012
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    ABSTRACT: Activated platelets form heterogeneous aggregates of platelets and monocytes, which are involved in a variety of inflammatory disorders. Some anti-human leukocyte antigen (HLA) Class I antibodies have been shown to activate platelets. Human leukocyte antigen-A2-positive or HLA-A2-negative platelets were incubated with HLA-A2-negative peripheral blood mononuclear cells (PBMNCs) in the presence of anti-HLA-A2 serum at 37°C. The binding of platelets to monocytes was analysed by flow cytometry. The levels of IL-1 β and IL-8 in the culture supernatant were determined by ELISA. Anti-HLA-A2 serum increased the formation of aggregates between monocytes and HLA-A2-positive platelets, but not HLA-A2-negative platelets, in a dose-dependent manner. Antiserum also increased the number of platelets bound to monocytes in a time-dependent manner. The addition of anti-P-selectin glycoprotein ligand (PSGL-1) mAb almost completely inhibited the formation of platelet-monocyte aggregates as well as the number of platelets bound to monocytes. When HLA-A2-positive or HLA-A2-negative platelets were incubated with HLA-A2-negative PBMNCs in the presence of anti-HLA-A2, the level of IL-1β and IL-8 in the supernatant of coculture was significantly higher in HLA-A2-positive platelets than in HLA-A2-negative platelets. The addition of anti-PSGL-1 mAb partially but significantly inhibited the production of both IL-1β and IL-8. The activation of platelets with anti-HLA Class I alloantibody caused the formation of platelet-monocyte aggregates, followed by the production of IL-1β and IL-8, in a cognate antigen-antibody manner. The adhesive interaction of P-selectin and PSGL-1 at least partially contributed to these phenomena.
    Vox Sanguinis 09/2011; 102(3):250-7. · 2.85 Impact Factor
  • T. Kato, T. Inoue, Y. Suzuoki
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    ABSTRACT: This study proposes a method to estimate the standard deviation (STD) of total power output fluctuation of high penetration photovoltaic power generation system (HP- PVS) dispersed in large area, so that the impact of HP-PVS on the load frequency control is discussed. First, by using the data of horizontal global insolation observed at 5 points in 25 km x 25 km area, the practical usefulness of STD is evaluated by comparing the STD with the maximum fluctuation width. Then, two key factors of the proposed model are discussed; the distance with which the insolation fluctuations at two points can be considered as independent, and the practical usefulness of the central limit theorem to estimate the STD of ensemble average fluctuation of insolation. Finally, assuming the geographical distribution of residential PVS, the STD of total power output fluctuation of HP-PVS dispersed in the service area of electric power utility is evaluated.
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    ABSTRACT:   In previous studies, we reported the transmission of hepatitis E virus (HEV) by transfusion, and the frequent detection of HEV markers in Japanese blood donors with elevated ALT levels. For the current study, we carried out a nationwide survey of the prevalence of IgG anti-HEV in qualified blood donors throughout Japan. The 12,600 samples from qualified blood donors were collected from seven blood centres (1800 per centre) representing nearly all regions of Japan. Samples were from age- and sex-matched blood donors who tested negative for all the current blood screening tests. The samples were screened using the in-house IgG anti-HEV ELISA. Sequentially, the positive samples were tested by the commercial IgG anti-HEV ELISA. Of 12,600 samples, 431 (3·4%) were regarded as positive for IgG anti-HEV. The prevalence of IgG anti-HEV was higher in eastern Japan (5·6%) than in western Japan (1·8%) (P<0·001), and was also age-dependent and higher in men (3·9%) than in women (2·9%) (P=0·002). The spread of the domestic infection of HEV was observed in qualified blood donors in Japan. A higher prevalence of IgG anti-HEV was observed in male donors, older donors and in donors residing in eastern Japan. Further studies are necessary to clarify the potential risk of transfusion-transmission of HEV in Japan.
    Vox Sanguinis 11/2010; 99(4):307-13. · 2.85 Impact Factor
  • Source
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    ABSTRACT: Anti-endothelial cell antibodies (AECA) have been frequently detected in systemic vasculitis, which affects blood vessels of various sizes. To understand the pathogenic roles of AECA in systemic vasculitis, we attempted to identify target antigens for AECA comprehensively by a proteomic approach. Proteins extracted from human umbilical vein endothelial cells (HUVEC) were separated by two-dimensional electrophoresis, and Western blotting was subsequently conducted using sera from patients with systemic vasculitis. As a result, 53 autoantigenic protein spots for AECA were detected, nine of which were identified by mass spectrometry. One of the identified proteins was peroxiredoxin 2 (Prx2), an anti-oxidant enzyme. Frequency of anti-Prx2 autoantibodies, measured by enzyme-linked immunosorbent assay (ELISA), was significantly higher in systemic vasculitis (60%) compared to those in collagen diseases without clinical vasculitis (7%, P < 0·01) and healthy individuals (0%, P < 0·01). Further, the titres changed in parallel with the disease activity during time-courses. The presence of anti-Prx2 autoantibodies correlated significantly with elevation of serum d-dimers and thrombin-antithrombin complex (P < 0·05). Immunocytochemical analysis revealed that live endothelial cells expressed Prx2 on their surface. Interestingly, stimulation of HUVEC with rabbit anti-Prx2 antibodies increased secretion of interleukin (IL)-6, IL-1β, IL-1ra, growth regulated oncogene (GRO)-α, granulocyte colony-stimulating factor (G-CSF), granulocyte macrophage colony-stimulating factor (GM-CSF), IL-8 and monocyte chemoattractant protein (MCP)-1 more than twofold compared to that of with rabbit immunoglobulin (Ig)G. Taken together, our data suggest that anti-Prx2 autoantibodies would be a useful marker for systemic vasculitis and would be involved in the inflammatory processes of systemic vasculitis.
    Clinical & Experimental Immunology 09/2010; 161(3):459-70. · 3.41 Impact Factor
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    ABSTRACT: We previously developed a novel additive solution (M-sol) with a high ability to preserve the in vitro qualities of platelets (PLTs) in washed PLTs Here, we compared the ability of M-sol with that of commercially available additive solutions (ASs) to preserve the in vitro qualities (pH, mean PLT volume, %disc, P-selectin, %hypotonic shock response and aggregation) of PLTs at a low plasma concentration. The platelet concentrate was divided into two equal aliquots (control group and test group). After centrifugation of both groups and removal of as much supernatant as possible, the pellet of the control group was resuspended in M-sol and those of the test group were resuspended in other ASs, and subsequently stored in polyolefin bags with agitating at 20-24 degrees C. Compared with those stored in M-sol, the qualities of PLTs stored in PAS-B (alternative name; PAS-II or T-sol), PAS- C (alternative name; PAS-III or Intersol) or Plasma Lyte were degraded as early as 24 h after washing. The qualities of PLTs stored in PAS-D (alternative name; Composol PS) or PAS-E (alternative name; PAS-IIIM or SSP+) were comparable to that of those stored in M-sol 24 h after washing; however, the qualities had deteriorated 72 h after washing. At a low plasma concentration (5% or less), the M-sol showed a higher ability to preserve PLTs than the five ASs studied here. Although PAS-D and PAS-E are available as an AS for short-term storage of washed PLTs, M-sol is thought to be preferable for longer storage.
    Vox Sanguinis 05/2010; 99(2):131-5. · 2.85 Impact Factor
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    ABSTRACT: The activation of neutrophils by human leukocyte antigen (HLA) Class I alloantibody is thought to be involved in transfusion-related acute lung injury. Neutrophils contain various biological substances in four groups of granules, including secretory vesicles, azurophilic granules, specific granules and gelatinase granules. To characterize the activation of neutrophils by HLA Class I alloantibody, we investigated whether HLA Class I alloantibody could cause the degranulation of these groups of granules either coordinately or selectively. Sera containing HLA-A24 alloantibody were incubated with neutrophils in a washed whole blood system. CD11b expression (secretory vesicles) on neutrophils was analysed by flow cytometry, and the secretion of markers of each granule was determined by ELISA. The treatment of cross-matching-positive neutrophils with sera containing HLA-A24 alloantibody caused the significant expression of CD11b, and the significant secretion of neutrophil elastase and myeloperoxidase, azurophilic granule markers and heparin-binding protein (HBP), which is localized in secretory vesicles and azurophilic granules when compared with cross-matching-negative neutrophils. In contrast, no significant differences were observed in the secretion of lactoferrin, a marker of specific granules, and matrix methalloproteinase-9, a marker of gelatinase granules between cross-matching-positive and cross-matching-negative cells upon stimulation with sera. CD11b expression and secretion of HBP by serum was partially inhibited by p38 mitogen-activated protein (MAP)-kinase inhibitors. Neutrophils activated with sera containing HLA Class I alloantibody caused the preferential degranulation of azurophilic granules and secretory vesicles. This process was at least in part mediated by p38 MAP kinase-involved signal transduction.
    Vox Sanguinis 02/2010; 98(4):560-6. · 2.85 Impact Factor
  • Osteoarthritis and Cartilage 01/2010; 18. · 4.26 Impact Factor
  • T. Kato, T. Inoue, Y. Suzuoki
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    ABSTRACT: Power output fluctuation of photovoltaic power generation systems (PVSs) may cause negative impact on the load frequency control of existing electric power system when the penetration of PVSs is quite large. For the cost-effective mitigation, the proper evaluation of apparent electricity load fluctuation property is very important, taking PVSs power output into account as negative load. Considering the independency of fluctuation patterns of insolation among various locations, this study evaluates the standard deviation of total power output fluctuation of PVSs by using the multi-point observation data of insolation. The diversity of PVSs penetration in the wide area is taken into account based on the statistical data of distribution of residences. Then, by taking the standard deviation of electricity load into account, this study discusses the impact of large-scale penetration of PVSs on the load frequency control.
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    ABSTRACT: On constructing a microgrid, it is essential to balance capacity of photovoltaic power generation (PV) systems and storage batteries in accordance with a control target. In the present study, we constructed a simulation model of energy control system in the microgrid. By using this model, we investigated the acceptable capacity of PV systems according the capacity of NaS battery for keeping the target supply-demand power imbalance over 30-min. within ±3 %. Under keeping the control target of power imbalance over 30 min. within ±3 %, we verified the relation between acceptable capacity of PV systems and NaS battery in a microgrid as follows. (1) the minimum required capacity of NaS battery in relation to the capacity of installed PV systems (330 kW) is of the order of ±20 kW, (2) the acceptable capacity of PV systems in relation to the capacity of installed NaS battery (±500 kW) is of the order of 890 kW. Moreover, we clarified the constrained conditions which impact to the power balancing in the microgrid according to the acceptable capacity of the PV systems.
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    ABSTRACT: Using proteomic analysis, we identified candidate autoantigens specific for central nervous system (CNS) involvement in systemic lupus erythematosus (SLE). Proteins, extracted from cultured human neuroblastoma cells, were separated both by SDS-PAGE (1-DE) and two-dimensional electrophoresis (2-DE), and transferred to membranes. Western blot analysis was performed using serum samples from 30 SLE patients with CNS involvement (CNS-Lupus) and from 30 SLE patients without CNS involvement (non-CNS-SLE). The detected autoantigens were identified using MALDI-TOF/TOF MS. On the 1-DE Western blot, we detected 32 antigenic bands in the serum samples from the CNS-Lupus patients. Among them, four bands were detected significantly more frequently in the CNS-Lupus patients than in the non-CNS-SLE patients. Three bands were detected in four or more of the CNS-Lupus patients but in only one or none of the non-CNS-SLE patients. We thus selected these seven bands for the next investigations. Next, we detected protein spots corresponding to the selected seven bands by 2-DE Western blot and identified four proteins. They are peroxiredoxin-4, ubiquitin carboxyl-terminal hydrolase isozyme L1, splicing factor arginine/serine-rich 3, and histone H2A type 1. These four candidate autoantigens for the anti-neuronal cell antibodies would be a useful marker for CNS-Lupus.
    Lupus 12/2009; 19(6):717-26. · 2.78 Impact Factor
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    ABSTRACT: In order to clarify the mechanism of electrical-tree inception from water-tree degradation which often determines the remaining life of power cables, we have been investigating electrical tree inception and propagation from water-tree degradation in polyethylene. Some of the results suggested that at higher temperatures the extent of water-tree degradation was much higher than that of water-tree degradation formed at lower temperatures. We, therefore, investigated the temperature dependence of water tree degradation and its effects on electrical tree inception. At 363 K, the water tree growth is much faster than low temperatures and the degradation is severer. When the water tree is wet, electrical tree inception voltage becomes higher, which is explained in terms of electrical-field moderation and suppression of electron acceleration due to the existence of water and so on. In the sample with water tree formed at 363 K, however, the increase in tree inception voltage is small. When the water tree is dry, water tree degradation tends to lower electrical tree inception voltage and to promote the degradation under prolonged ac voltage application. These are explained by structural change due to water tree degradation, such as scission of polymer chains and micro void formation.
    Electrical Insulation and Dielectric Phenomena, 2009. CEIDP '09. IEEE Conference on; 11/2009
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    ABSTRACT: Power output fluctuation of photovoltaic power generation systems (PVSs) may cause negative impact on the existing electric power system when the penetration of PVSs is quite large. A micro-grid consisting of clustered PVSs and a battery system would be one of the promising measures to the negative impact of clustered PVSs, while the maximum power and storage capacity of battery system should be reduced as much as possible from the economic point of view. Because of the difference in output fluctuation among PVSs in the various locations, the total output fluctuations of PVSs would be relaxed due to the so-called "smoothing-effect". Considering such the effect, the required performance of battery system can be reduced, even though small output fluctuation of each micro-grid still remains. By using data on solar irradiance observed in five points simultaneously, this study evaluates the total output fluctuation of several micro-grids and the required performance of battery system, taking the smoothing effect into account.
    Sustainable Alternative Energy (SAE), 2009 IEEE PES/IAS Conference on; 10/2009
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    ABSTRACT: High temperature superconducting (HTS) cables are expected as a large capacity cable with lower transmission loss. Numerous HTS cable demonstration projects using Bi-2223 superconducting wires are being promoted around the world for practical utility usage. RE-123 coated conductors, which are still at the research and development stage, will also be applied to several demonstration projects in coming years in addition to Sumitomo Electric's world first 30-m HTS cable project using RE-123 conductors which was successfully energized in early 2008. As wire and cable manufacturer, Sumitomo Electric has also been developing it's own RE-123 conductors, and has succeeded in fabricating a 200-m-class conductor. One of the important challenges associated with the use of RE-123 conductors in power cables is to ensure stability against over-current. In order to evaluate over-current characteristics, a 10-meter ldquo3-in-Onerdquo RE-123 superconducting cable was manufactured and over-current tests were performed. No Ic degradation was observed after exposure to over-currents with a maximum current of 31.5 kArms for 2 s (120 cycles), which meets the requirements for 66-77 kV class power cables in Japan. It was confirmed that RE-123 conductors have satisfactory over-current characteristics for use as superconducting cable wires.
    IEEE Transactions on Applied Superconductivity 07/2009; · 1.20 Impact Factor

Publication Stats

5k Citations
1,143.38 Total Impact Points


  • 1993–2012
    • Nagoya University
      • • Department of Electrical Engineering and Computer Science
      • • Center for Integrated Research in Science and Engineering (CIRSE)
      Nagoya, Aichi, Japan
  • 1990–2012
    • Tokyo University of Science
      • Department of Applied Biological Science
      Edo, Tōkyō, Japan
  • 2006–2011
    • Japanese Red Cross
      Edo, Tōkyō, Japan
    • Fujita Health University
      • Department of Physiology
      Nagoya, Aichi, Japan
  • 1992–2010
    • St. Marianna University School of Medicine
      • • Institute of Medical Science
      • • Clinical Proteomics and Molecular Medicine
      • • Department of Medicine
      Kawasaki, Kanagawa-ken, Japan
  • 2007
    • Nippon Medical School
      • Department of Rheumatology
      Tokyo, Tokyo-to, Japan
  • 1982–2007
    • Aichi Cancer Center
      Ōsaka, Ōsaka, Japan
  • 2004
    • University of Leicester
      • Department of Engineering
      Leicester, ENG, United Kingdom
  • 1981–2003
    • Nagoya City University
      • • Department of Internal Medicine
      • • Department of Orthopedic Surgery
      • • Department of Neurosurgery (Hospital)
      • • Department of Biochemistry
      • • Medical School
      Nagoya, Aichi, Japan
  • 2001
    • Nagoya Second Red Cross Hospital
      Nagoya, Aichi, Japan
    • Aichi Human Service Center
      Касугай, Aichi, Japan
    • Kanazawa University
      • Department of Biophysical Genetics
      Kanazawa, Ishikawa, Japan
  • 1999–2001
    • Saitama Medical University
      • Saitama Medical Center
      Saitama, Saitama-ken, Japan
  • 1997–2001
    • Aichi Medical University
      • Division of Internal Medicine
      Okazaki, Aichi, Japan
  • 2000
    • The University of Calgary
      • Department of Biochemistry and Molecular Biology
      Calgary, Alberta, Canada
  • 1992–1998
    • Tokyo Medical and Dental University
      • • Department of Internal Medicine
      • • Department of Medicine
      Edo, Tōkyō, Japan
  • 1994–1997
    • University of Mississippi Medical Center
      • Department of Physiology and Biophysics
      Jackson, MS, United States
  • 1992–1997
    • The University of Tokyo
      • Faculty & Graduate School of Medicine
      Tokyo, Tokyo-to, Japan
  • 1995
    • Chiba University
      Tiba, Chiba, Japan
  • 1987–1994
    • Gunma University
      • Department of Clinical Laboratory Medicine
      Maebashi, Gunma Prefecture, Japan
  • 1983–1985
    • Tokyo Institute of Technology
      • Chemistry Department
      Tokyo, Tokyo-to, Japan
  • 1979–1981
    • University of Chicago
      Chicago, Illinois, United States