著者

Yusuke Miwa Ryo Takahashi Yuzo Ikari Airi Maeoka Shinichiro Nishimi Nao Oguro Tomoki Hayashi Mika Hatano Sakiko Isojima Ryo Yanai Tsuyoshi Kasama Yoichi Toyoshima Katsunori Inagaki Kenji Sanada

出版者

一般社団法人 日本内科学会

雑誌

Internal Medicine (ISSN:09182918)

巻号頁・発行日

vol.56, no.8, pp.903-906, 2017-04-15 (Released:2017-04-15)

参考文献数

15

被引用文献数

12

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Objective Although previous studies have reported the prognostic factors for functional remission, no reports have cited the predictive factors. Our aim was to study the predictive factors for functional remission, which is a treatment goal in rheumatoid arthritis (RA), after receiving biological disease-modifying antirheumatic drugs (bDMARDs) treatment for six months. Methods The study consisted of 333 RA patients treated with bDMARDs for six months. The following patient characteristics were investigated: age, gender, disease duration, type of bDMARDs, baseline steroid and methotrexate dosage, and levels of serum rheumatoid factor, matrix metalloprotease, anti-cyclic citrullinated peptides antibody, tumor necrosis factor-α, and interleukin-6. In our evaluation, we used the Simplified Disease Activity Index (SDAI) for RA disease activity, health assessment questionnaire disability index (HAQ-DI) for activity of daily living, Short Form (SF)-36 for quality of life, and Hamilton Depression Rating Scale (HAM-D) or Self-rating Depression Scale (SDS) to determine the patients' depression status. The subjects were divided into two groups: patients with HAQ-DI≤0.5 and HAQ-DI>0.5 at 6 months. Results A univariate analysis comparing a group of RA patients without functional remission (n=68) showed that the patients with functional remission (n=164) had the following in common compared with those without remission: younger age, shorter disease duration, lower baseline steroid dosage, lower SDAI, lower HAQ-DI, higher SF-36, and lower HAM-D. Only lower HAQ-DI scores and "mental health" score on the SF-36 were detected using a logistic regression analysis. Conclusion These findings suggested that RA patients with lower HAQ-DI and lower depression scores at baseline were more likely to achieve functional remission using bDMARDs treatment than those without these variables.

著者

Ryo TAKAHASHI Hidenori MATSUO Sijie XIA Qiang CHEN Fumiyuki ADACHI

出版者

The Institute of Electronics, Information and Communication Engineers

雑誌

IEICE TRANSACTIONS on Communications (ISSN:09168516)

巻号頁・発行日

vol.E106-B, no.9, pp.748-757, 2023-09-01

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Cell-free massive MIMO (CF-mMIMO), which cooperatively utilizes a large number of antennas deployed over a communication area, has been attracting great attention as an important technology for realizing 5G-advanced and 6G systems. Recently, to ensure system scalability and mitigate inter-user interference in CF-mMIMO, a user-centric (UC) approach was investigated. In this UC approach, user-centric antenna-sets are formed by selecting appropriate antennas for each user, and postcoding is applied to reduce the strong interference from users whose antenna-sets overlap. However, in very high user density environments, since the number of interfering users increases due to increased overlapping of antenna-sets, the achievable link capacity may degrade. In this paper, we propose a user-cluster-centric (UCC) approach, which groups neighborhood users into a user-cluster and associates the predetermined number of antennas to this user-cluster for spatial multiplexing. We derive the uplink postcoding weights and explain the effectiveness of the proposed UCC approach in terms of the computational complexity of the weight computation. We also compare the uplink user capacities achievable with UC and UCC approaches by computer simulation and clarify situations where the UCC approach is effective. Furthermore, we discuss the impact of the number of interfering users considered in the zero-forcing and minimum mean square error postcoding weight computation on the user capacity.

著者

高橋 遼 Ryo TAKAHASHI 目白研心中学校・高等学校教諭

雑誌

目白大学短期大学部研究紀要 = Memoirs of Mejiro University College (ISSN:13462210)

巻号頁・発行日

vol.(52), pp.1-15, 2016

著者

Ryo TAKAHASHI Ken UMENO

出版者

The Institute of Electronics, Information and Communication Engineers

雑誌

IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences (ISSN:09168508)

巻号頁・発行日

vol.E97-A, no.7, pp.1619-1622, 2014-07-01

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In this study, a performance of a synchronous code division multiple access (CDMA) using the chaotic spreading sequences with constant power is estimated in indoor power line fading channels. It is found that, in the fading channels, as the number of simultaneous users increases, the chaotic spreading sequences realize better performance than the Walsh-Hadamard sequences in the synchronous CDMA.

著者

Ryo Takahashi Etsushi Nameda Ken Umeno

出版者

The Japan Society for Industrial and Applied Mathematics

雑誌

JSIAM Letters (ISSN:18830609)

巻号頁・発行日

vol.2, pp.9-12, 2010 (Released:2010-03-09)

参考文献数

9

被引用文献数

2 1

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Inner angle of triangle made of consecutive three points on unit circle is investigated. We use two methods to plot points. One is plotting random numbers whose distribution is uniform. Another is plotting consecutive numbers obtained by a map which generates complex chaotic sequences with constant power. We focus on an inner angle at the middle point in consecutive three points. An angle for chaotic sequence is found to be different from one for uniform random sequence.