著者
Hideki Kakeya Yoshihisa Matsumoto
出版者
Information Processing Society of Japan
雑誌
IPSJ Transactions on Bioinformatics (ISSN:18826679)
巻号頁・発行日
vol.15, pp.22-29, 2022 (Released:2022-11-16)
参考文献数
35

A method to find a probability that a given bias of mutations occur naturally is proposed to test whether a newly detected virus is a product of natural evolution or a product of non-natural process such as genetic manipulation. The probability is calculated based on the neutral theory of molecular evolution and binominal distribution of non-synonymous (N) and synonymous (S) mutations. Though most of the conventional analyses, including dN/dS analysis, assume that any kinds of point mutations from a nucleotide to another nucleotide occurs with the same probability, the proposed model takes into account the bias in mutations, where the equilibrium of mutations is considered to estimate the probability of each mutation. The proposed method is applied to evaluate whether the Omicron variant strain of SARS-CoV-2, whose spike protein includes 29 N mutations and only one S mutation, can emerge through natural evolution. The result of binomial test based on the proposed model shows that the bias of N/S mutations in the Omicron spike can occur with a probability of 2.0 × 10-3 or less. Even with the conventional model where the probabilities of any kinds of mutations are all equal, the strong N/S mutation bias in the Omicron spike can occur with a probability of 3.7 × 10-3, which means that the Omicron variant is highly likely a product of non-natural process including artifact.
著者
Hideki Kakeya Ken Okada Hayato Takahashi
出版者
The Institute of Image Information and Television Engineers
雑誌
ITE Transactions on Media Technology and Applications (ISSN:21867364)
巻号頁・発行日
vol.6, no.3, pp.237-246, 2018 (Released:2018-07-01)
参考文献数
25
被引用文献数
10

This paper presents a full-HD autostereoscopic display with a wide viewing zone based on time-division multiplexing slanted parallax barrier with subpixel-based slit control. A slanted directional diffuser placed between the barrier panel and the image panel suppresses moir_ by mixing light from RGB subpixels. By constituting the parallax barrier along with this slanted diffusion line, control of the barrier by subpixel unit is enabled. By introducing subpixel-based phase shift and slit width control to time-division quadruplexing parallax barrier, viewing zone free from crosstalk is enlarged notably. Theoretical viewing zone is calculated and compared with the experimental results using a prototype hardware. The overall crosstalk of the prototype is also measured to confirm the effectiveness of the proposed method.
著者
Garimagai Borjigin Hideki Kakeya
出版者
The Institute of Image Information and Television Engineers
雑誌
ITE Transactions on Media Technology and Applications (ISSN:21867364)
巻号頁・発行日
vol.9, no.1, pp.80-85, 2021 (Released:2021-01-01)
参考文献数
22
被引用文献数
1 2

In this paper, we propose autostereoscopic displays with novel directional backlight designs. A high level of stereoscopic crosstalk is the main problem to be solved in the conventional systems. To reduce crosstalk, we propose a directional backlight system that suppresses the effect of field curvature only with a single layer of curved lens array. It is confirmed that the crosstalk level is reduced notably by the proposed methods. The uniformity of backlight intensity is also increased by using a lens array composed of trapezoid elemental lenses in place of rectangle elemental lenses.
著者
Bin Yang Hideki Kakeya
出版者
The Institute of Image Information and Television Engineers
雑誌
ITE Transactions on Media Technology and Applications (ISSN:21867364)
巻号頁・発行日
vol.9, no.2, pp.136-142, 2021 (Released:2021-04-01)
参考文献数
15
被引用文献数
1

We propose an autostereoscopic display allowing two observers with adaptive fractional time-division multiplexing parallax barrier. Fractional time-division suppresses perceived flickers when the order of slit position is properly set. To make sure that both of the observers are located in the proper viewing zones to enable stereoscopy simultaneously, the number of time-division multiplexing is switched in accordance with the distance between them. The viewing zone without crosstalk for the second viewer is evaluated theoretically.
著者
Hideki Kakeya Atsushi Yoshida Bin Yang Yukio Oshiro Nobuhiro Ohkohchi
出版者
The Institute of Image Information and Television Engineers
雑誌
ITE Transactions on Media Technology and Applications (ISSN:21867364)
巻号頁・発行日
vol.6, no.1, pp.11-17, 2018 (Released:2018-01-01)
参考文献数
20
被引用文献数
2

We present a liver surgery simulator using full-HD autostereoscopic displays. We have developed two kinds of autostereoscopic displays to keep on showing a full-HD 3D image to a viewer who moves freely in front of the display. One is a 3D display based on time-division multiplexing directional backlight and the other is a 3D display based on time-division multiplexing parallax barrier. We have applied the developed simulator using the 3D displays with different specifications to the education of medical students. The result of the questionnaires suggests that 3D visualization is effective and that reduction of crosstalk plays an important role to promote medical use of 3D displays.