23 research outputs found
Structural equation modeling with latent variables for diffusion processes and its application to sparse estimation
We consider structural equation modeling (SEM) with latent variables for
diffusion processes based on high-frequency data. The quasi-likelihood
estimators for parameters in the SEM are proposed. The goodness-of-fit test is
derived from the quasi-likelihood ratio. We also treat sparse estimation in the
SEM. The goodness-of-fit test for the sparse estimation in the SEM is
developed. Furthermore, the asymptotic properties of our proposed estimators
are examined.Comment: 91pages. arXiv admin note: substantial text overlap with
arXiv:2210.1167
Electrochemical Adsorption on Pt Nanoparticles in Alkaline Solution Observed Using In Situ High Energy Resolution X-ray Absorption Spectroscopy
The oxygen reduction reaction (ORR) on Pt/C in alkaline solution was studied by in situ high energy resolution X-ray absorption spectroscopy. To discuss the X-ray absorption near-edge structure (XANES), this paper introduced the rate of change of the Δμ (RCD), which is an analysis method that is sensitive to surface adsorption. The surface adsorptions as hydrogen (below 0.34 V), superoxide anion (from 0.34 V to 0.74 V), hydroxyl species (from 0.44 V to 0.74 V), atomic oxygen (above 0.74 V), and α-PtO2 (above 0.94 V) were distinguished. It is clarified that the catalytic activity in an alkaline solution is enhanced by the stability of atomic oxygen and the low stability of superoxide anion/peroxide adsorption on the platinum surface
Electrochemical Adsorption on Pt Nanoparticles in Alkaline Solution Observed Using In Situ High Energy Resolution X-ray Absorption Spectroscopy
The oxygen reduction reaction (ORR) on Pt/C in alkaline solution was studied by in situ high energy resolution X-ray absorption spectroscopy. To discuss the X-ray absorption near-edge structure (XANES), this paper introduced the rate of change of the ∆μ (RCD), which is an analysis method that is sensitive to surface adsorption. The surface adsorptions as hydrogen (below 0.34 V), superoxide anion (from 0.34 V to 0.74 V), hydroxyl species (from 0.44 V to 0.74 V), atomic oxygen (above 0.74 V), and α-PtO2 (above 0.94 V) were distinguished. It is clarified that the catalytic activity in an alkaline solution is enhanced by the stability of atomic oxygen and the low stability of superoxide anion/peroxide adsorption on the platinum surface
大学における教員養成の展開をめぐる研究動向
はじめに / 1.教育刷新委員会における戦後教員養成制度の成立 / 2.国立大学における「教育学部」の成立 / おわり
Data-Retention-Voltage-Based Analysis of Systematic Variations in SRAM SEU Hardness: A Possible Solution to Synergistic Effects of TID
Single-event upset (SEU) hardness varies across dies, wafers, and lots—even just after fabrication and further across time. Mechanisms of postfabrication variations include total ionizing dose (TID) effects, which are caused by long-term radiation exposure. This synergistic effect of TID on SEU hardness is a particular concern in integrated circuits used in space and nuclear radiation environments. This article shows that an electrical parameter called the data-retention voltage is useful in dealing with such TID effects on the SEU hardness of static random access memories (SRAMs), which are known to be particularly radiation-sensitive. Experiments showed that TID-induced variations in SRAM SEU hardness, i.e., variations in SEU cross sections, were predicted by measuring the data-retention voltage. In addition, these variations were canceled out by adjusting the power supply voltage according to its interesting relationship to the data-retention voltage. Results suggest that it might be possible in flight to predict and cancel out SEU hardness variations caused by TID and other synergistic effects
Intrabiliary growth type of metastasis from colon cancer, 12 years after curative colectomy: a case report
Abstract Background Liver is a common location of colorectal metastasis, but intrabiliary growth of liver metastasis is not well recognized. Furthermore, intrabiliary metastasis that discovered over 10 years after excision has rarely been described. Case presentation An 80-year-old man was admitted due to the presence of a liver mass in segment 5 (S5) concomitant with elevated carcinoembryonic antigen (CEA), and carbohydrate antigen (CA) 19–9. He underwent right hemicolectomy for colon cancer 12 years prior. Enhanced computed tomography (CT) showed dilated bile ducts with periductal enhancement in S5; hence, cholangiocarcinoma was suspected. Upon anterior segmentectomy, we observed that the cut surface of the specimen exhibited a yellowish-white tumor within the bile ducts. Histologically, the tumor formed within the papillary process, extended along the lumen, and replaced the normal bile duct epithelium. Immunohistochemical studies showed that the liver tumor and primary colon cancer were negative for cytokeratin (CK) 7 and positive for CK20 and Caudal-type homeobox transcription factor 2 (CDX-2). In addition, both tumors showed a same KRAS mutation. We diagnosed the liver tumor as liver metastasis recurrence from colon cancer. Conclusion Intrabiliary growth type of metastasis (IGM) is difficult to distinguish from cholangiocarcinoma, and sometimes develops long after surgery; thus, careful examination of a patient’s history is needed in such cases
Investigation of Buried-Well Potential Perturbation Effects on SEU in SOI DICE-Based Flip-Flop Under Proton Irradiation
:The effects of buried-well potential perturbation under the buried-oxide (BOX) layer are studied in both a heavy-ion single event upset (SEU) test and a high-energy proton-SEU test of a silicon-on-insulator (SOI) dual interlocked storage cell (DICE)-based flip-flop. Their dependence on incident angle and back bias is discussed. We fabricated both DICE-based flip-flop and conventional flip-flop, which are designed as 80 000-stage shift-register chains. In a heavy-ion test, a considerable number of SEUs were observed at back bias exceeding 2.4 V, and a ten-times larger SEU-cross section was finally recorded at back bias of 3.0 V compared with the total active area of a DICE-based flip-flop cell. This marks the first case where DICE topology was found to be broken by buried-well potential perturbation on an SOI DICE-based flip-flop. In a proton test, one error was observed at back bias of 2.0 V. The SEU rate in the Van Allen belt at an altitude of 2300 km and an inclination of 90° was estimated as being once every 5 years