Analysis of integrated IDFT and Zadoff–Chu matrix precoding processes in OFDM systems

Ohuchi Kouji 한국통신학회 2025 ICT Express Vol.11 No.2

Peak signal reduction is a critical problem in orthogonal frequency-division multiplexing (OFDM) systems. Herein, we focus on Zadoff–Chu matrix (ZCM) precoding as a peak signal reduction method and analyze its integration using the discrete Fourier transform process. The analysis reveals that the integrated process can be substituted by a sparse matrix multiplication and the influence of ZCM parameters on the sparse matrix is mathematically clarified. The results also show that the ZCM precoding works to produce a single-carrier signal and explains how the ZCM precoding reduces the peak of the OFDM signal.

Reduction of Outdoor and Indoor Ambient Dose Equivalent after Decontamination in the Fukushima Evacuation Zones

Yoshida-Ohuchi, Hiroko,Kanagami, Takashi,Naitoh, Yutaka,Kameyama, Mizuki,Hosoda, Masahiro The Korean Association for Radiation Protection 2017 방사선방어학회지 Vol.42 No.1

Background: One of the most urgent issues following the accident at the Fukushima Daiichi nuclear power plant (FDNPP) was the remediation of the land, in particular, for residential area contaminated by the radioactive materials discharged. In this study, the effect of decontamination on reduction of ambient dose equivalent outdoors and indoors was evaluated. The latter is essential for residents as most individuals spend a large portion of their time indoors. Materials and Methods: From December 2012 to November 2014, thirty-seven Japanese single-family detached wooden houses were investigated before and after decontamination in evacuation zones. Outdoor and indoor dose measurements (n = 84 and 114, respectively) were collected based on in situ measurements using the NaI (Tl) scintillation surveymeter. Results and Discussion: The outdoor ambient dose equivalents [$H^*(10)_{out}$] ranged from 0.61 to $3.71{\mu}Sv\;h^{-1}$ and from 0.23 to $1.32{\mu}Sv\;h^{-1}$ before and after decontamination, respectively. The indoor ambient dose equivalents [$H^*(10)_{in}$] ranged from 0.29 to $2.53{\mu}Sv\;h^{-1}$ and from 0.16 to $1.22{\mu}Sv\;h^{-1}$ before and after decontamination, respectively. The values of reduction efficiency (RE), defined as the ratio by which the radiation dose has been reduced via decontamination, were evaluated as $0.47{\pm}0.13$, $0.51{\pm}0.13$, and $0.58{\pm}0.08$ ($average{\pm}{\sigma}$) when $H^*(10)_{out}$ < $1.0{\mu}Sv\;h^{-1}$, $1.0{\mu}Sv\;h^{-1}$ < $H^*(10)_{out}$ < $2.0{\mu}Sv\;h^{-1}$, and $2.0{\mu}Sv\;h^{-1}$ < $H^*(10)_{out}$, respectively, indicating the values of RE increased as $H^*(10)_{out}$ increased. It was found that the values of RE were $0.53{\pm}0.12$ outdoors and $0.41{\pm}0.09$ indoors, respectively, indicating RE was larger outdoors than indoors. Conclusion: Indoor dose is essential as most individuals spend a large portion of their time indoors. The difference between outdoors and indoors should be considered carefully in order to estimate residents' exposure dose before their returning home.

Evaluation of bone mineral density and bone strength in autochthonous transgenic model mice for diabetes mellitus (Akita mice)

Kentaro Ohuchi,Naohisa Miyakoshi,Yuji Kasukawa,Toyohito Segawa,Hayato Kinoshita,Yoichi Shimada 대한골다공증학회 2015 Osteoporosis and Sarcopenia Vol.1 No.2

Objectives: Diabetes mellitus (DM) causes secondary osteoporosis, which reduces bone mineral density (BMD) and bone strength. Akita mice (AM) are DM model mice used to evaluate glucose metabolism. However, bone metabolism in AM remains unclear. The purpose of this study was to evaluate BMD, bone strength, and serum sclerostin levels in AM. Methods: Female AM and control mice (C57/BL/6NCrSlc; CM) were divided into four groups: (1) a CM group sacrificed at 14 (CM-14w; n ¼ 8) or (2) 18 weeks of age (CM-18w; n ¼ 6); and (3) an AM group sacrificed at 14 (AM-14w; n ¼ 9) or (4) 18 weeks of age (AM-18w; n ¼ 6). Blood glucose level, serum sclerostin level, total tibial BMD, and femoral shaft bone strength were evaluated at each time point. Results: Blood glucose levels were significantly higher in AM than in CM (p < 0.001). Serum sclerostin levels were significantly lower in AM- 18w than in CM-18w (p < 0.001). BMD was significantly lower in AM-14w than in CM-14w (p ¼ 0.004). Stiffness of the femoral shaft was significantly lower in AM-18w than in CM-14w (p ¼ 0.04). Body weight (r ¼ 0.608, p < 0.01) and maximum load (r ¼ 0.438, p < 0.05) were significantly positively correlated with serum sclerostin levels, while blood glucose levels showed a significant negative correlation (r¼?0.708, p < 0.01). Conclusions: AM showed decreased BMD and bone strength with lower levels of serum sclerostin than CM. © 2015 The Korean Society of Osteoporosis. Production and hosting by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

Effects of teriparatide on bone in autochthonous transgenic model mice for diabetes mellitus (Akita mice)

Kentaro Ohuchi,Naohisa Miyakoshi,Yuji Kasukawa,Toyohito Segawa,Hayato Kinoshita,Chie Sato,Masashi Fujii,Yoichi Shimada 대한골다공증학회 2019 Osteoporosis and Sarcopenia Vol.5 No.4

Objectives: The purpose of this study is to evaluate the effects of teriparatide (TPTD) on bone mineral density (BMD), bone strength, and bone quality in Akita mouse models of diabetes mellitus. Methods: Twelve-week-old female Akita mice and control mice (C57/BL/6NCrSlc) were divided into 4 groups: control mice treated with vehicle (n ¼ 7) or TPTD (n ¼ 6); and Akita mice treated with vehicle (n ¼ 6) or TPTD (n ¼ 7). TPTD or vehicle was administered subcutaneously 3 times a week for 8 weeks. Blood glucose, serum sclerostin, total tibial BMD, femoral shaft bone strength, and bone quality using Fourier-transform infrared spectroscopy imaging were evaluated. Results: No significant differences in serum sclerostin levels were evident among these groups after 8 weeks of treatment. TPTD significantly increased BMD in control mice (þ12.7%, P ¼ 0.02) and Akita mice (þ29.2%, P ¼ 0.001) compared with vehicle. Maximum load and stiffness were significantly higher in Akita mice treated with TPTD than in Akita mice treated with vehicle (þ56.6%, P ¼ 0.03 and þ 90.5%, P ¼ 0.02, respectively). On Fourier-transform infrared spectroscopy imaging, the mineral/matrix ratio was significantly lower in Akita mice treated with vehicle than in control mice (12.2%, P ¼ 0.02), and TPTD treatment significantly increased the mineral/matrix ratio (P ¼ 0.003). Conclusions: TPTD thus improved BMD and bone strength in both control mice and Akita mice, with improvements in the mineral/matrix ratio among Akita mice.

Where Is the “Optimal” Fontan Hemodynamics?

Hideo Ohuchi 대한심장학회 2017 Korean Circulation Journal Vol.47 No.6

Fontan circulation is generally characterized by high central venous pressure, low cardiac output, and slightly low arterial oxygen saturation, and it is quite different from normal biventricular physiology. Therefore, when a patient with congenital heart disease is selected as a candidate for this type of circulation, the ultimate goals of therapy consist of 2 components. One is a smooth adjustment to the new circulation, and the other is long-term circulatory stabilization after adjustment. When either of these goals is not achieved, the patient is categorized as having “failed” Fontan circulation, and the prognosis is dismal. For the first goal of smooth adjustment, a lot of effort has been made to establish criteria for patient selection and intensive management immediately after the Fontan operation. For the second goal of long-term circulatory stabilization, there is limited evidence of successful strategies for long-term hemodynamic stabilization. Furthermore, there have been no data on optimal hemodynamics in Fontan circulation that could be used as a reference for patient management. Although small clinical trials and case reports are available, the results cannot be generalized to the majority of Fontan survivors. We recently reported the clinical and hemodynamic characteristics of early and late failing Fontan survivors and their association with all-cause mortality. This knowledge could provide insight into the complex Fontan pathophysiology and might help establish a management strategy for long-term hemodynamic stabilization.

Analysis of chamical mediators and cytokines in allergic inflammation models in rats and their advantages for the screening of anti-allergic inflammatory drugs

(Kazuo Ohuchi) 한국응용약물학회 1996 학술대회 Vol.1996 No.1

Emergent Organization with Pheromone Communication in Multiple Monkey Banana Problem

Keiji Suzuki,Azuma Ohuchi 대한전자공학회 1997 ITC-CSCC :International Technical Conference on Ci Vol.- No.-

A Construction of Participants Assistance System in Collaborative Communication Environments

Hajime Saitoh,Azuma Ohuchi,Takashi Maeda 대한전자공학회 1998 ITC-CSCC :International Technical Conference on Ci Vol.- No.-

Is glue embolization safe and effective for gastrointestinal bleeding?

Shinsaku Yata,Yasufumi Ohuchi,Akira Adachi,Masayuki Endo,Shohei Takasugi,Kazumichi Tsukam,Kensuke Matsumoto,Mika Kodani,Jun Makishima,Shinya Fujii 소화기인터벤션의학회 2018 Gastrointestinal Intervention Vol.7 No.3

Transcatheter arterial embolization using N-butyl-2-cyanoacrylate (NBCA) for gastrointestinal arterial bleeding enables higher cessation rate and lower recurrent bleeding rate compared with conventional embolic materials including gelatin sponge, metallic coil, and polyvinyl alcohol (PVA) particle. Glue embolization is particularly effective in patients with coagulopathy. Even in the lower gastrointestinal tract, ischemic bowel complications by glue embolization are comparable to other agents. Glue embolization is also effective for arterial esophageal bleeding without any serious ischemic complications although the anatomy of the esophageal artery is complex and varied. For bleeding after abdominal surgery such as pancreaticoduodenectomy or hepatic lobectomy, interventional radiologists should be careful with indicating glue embolization because the presence of fewer collateral vessels can easily result in serious ischemic complications. Modified glue such as Glubran 2 (NBCA associated with methacryloxyfulfolane) can reduce the risk of ischemic complication due to its less thermal reaction, but the outcomes seem unsatisfactory.

Is glue embolization safe and effective for gastrointestinal bleeding?

Shinsaku Yata,Yasufumi Ohuchi,Akira Adachi,Masayuki Endo,Shohei Takasugi,Kazumichi Tsukam,Kensuke Matsumoto,Mika Kodani,Jun Makishima,Shinya Fujii 소화기인터벤션의학회 2018 International journal of gastrointestinal interven Vol.7 No.3

Transcatheter arterial embolization using N-butyl-2-cyanoacrylate (NBCA) for gastrointestinal arterial bleeding enables higher cessation rate and lower recurrent bleeding rate compared with conventional embolic materials including gelatin sponge, metallic coil, and polyvinyl alcohol (PVA) particle. Glue embolization is particularly effective in patients with coagulopathy. Even in the lower gastrointestinal tract, ischemic bowel complications by glue embolization are comparable to other agents. Glue embolization is also effective for arterial esophageal bleeding without any serious ischemic complications although the anatomy of the esophageal artery is complex and varied. For bleeding after abdominal surgery such as pancreaticoduodenectomy or hepatic lobectomy, interventional radiologists should be careful with indicating glue embolization because the presence of fewer collateral vessels can easily result in serious ischemic complications. Modified glue such as Glubran 2 (NBCA associated with methacryloxyfulfolane) can reduce the risk of ischemic complication due to its less thermal reaction, but the outcomes seem unsatisfactory.