Dynamic Error Control for Wireless ATM Networks

Kentaro Yamada,Tomoyuki Tsuchiya,Hiromi Okada 대한전자공학회 1998 대한전자공학회 심포지엄 논문집 Vol.3 No.-

Some New Approaches to Fatigue Evaluation of Steel Bridges

Kentaro Yamada 한국강구조학회 2006 International Journal of Steel Structures Vol.6 No.4

For fatigue durability evaluation of stel bridges, fatigue strength of welded joints, i.e. S-N diagrams, stres ranges andstrength evaluation, 1 m method, is first presented. For the stress measurement of existing bridges strain checker, orstethoscope, is conveniently used at bridge sites. Bridge Weigh-in-Motion using reaction force method is effectively measureaxle weight of trucks in service, and the data can be used for fatigue durability evaluation of members related to axle loading,such as orthotropic steel decks.

High-energy Magnetic Excitations in Underdoped La1.90Sr0.10CuO4

Kentaro Sato,Masato Matsuura,Masaki Fujita,Ryoichi Kajimoto,Sungdae Ji,Kazuhiko Ikeuchi,Mitsutaka Nakamura,Yasuhiro Inamura,Masatoshi Arai,Masanori Enoki,Kazuyoshi Yamada 한국물리학회 2013 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.62 No.12

We measured the magnetic excitations in underdoped (UD) La1.90Sr0.10CuO4 by using inelasticneutron scattering over a wide energy range. We succeeded in observing the high-energy excitationsup to '160 meV. Hour-glass-like magnetic excitation, which is commonly seen in the superconductingphase of cuprate oxides, was confirmed. The Ecross (the energy where the dispersion is closestto the ( 12 , 12 ) reciprocal position) of 40 meV follows a linear relation between Ecross and the dopedhole concentration in the UD region. From the dispersion of high-energy excitations above Ecross,we successfully found an effective nearest neighbor interaction (Jeff ) of 102 ± 2 meV. This Jeff issmaller than the nearest neighbor interaction J(=132 meV) in the parent compound La2CuO4,indicating a reduction of Jeff by hole-doping.

Catalytic application of shape-controlled Cu₂O particles protected by Co₃O₄ nanoparticles for hydrogen evolution from ammonia borane

Yamada, Yusuke,Yano, Kentaro,Fukuzumi, Shunichi The Royal Society of Chemistry 2012 ENERGY AND ENVIRONMENTAL SCIENCE Vol.5 No.1

<p>Cu<SUB>2</SUB>O particles are active catalysts for hydrogen evolution from ammonia borane (AB) by hydrolysis, however, Cu<SUB>2</SUB>O particles easily form agglomerates as a result of highly reduced conditions during the reaction. In order to suppress agglomerate formation, capping of Cu<SUB>2</SUB>O with organic reagents or inorganic materials was performed and the catalytic reactivity in AB hydrolysis was examined. Among the examined methods, capping of Cu<SUB>2</SUB>O particles with Co<SUB>3</SUB>O<SUB>4</SUB> nanoparticles was the most effective to avoid agglomerate formation of Cu<SUB>2</SUB>O particles. The finding enabled us to examine the shape effect of Cu<SUB>2</SUB>O particles on the catalytic reactivity in AB hydrolysis in the presence of Co<SUB>3</SUB>O<SUB>4</SUB> nanoparticles. Comparisons of turnover frequencies for hydrogen evolution of Cu<SUB>2</SUB>O–Co<SUB>3</SUB>O<SUB>4</SUB> composites, in which Cu<SUB>2</SUB>O particles were in the shape of 50-facets, cube, octahedron or rhombicuboctahedron, indicated that the composite with Cu<SUB>2</SUB>O with the shape of 50-facets showed more than 7-fold higher hydrogen evolution rate normalized by surface area than the composite with Cu<SUB>2</SUB>O with the octahedral shape. The size and shape effects of Co<SUB>3</SUB>O<SUB>4</SUB> nanoparticles were also investigated on their ability to protect Cu<SUB>2</SUB>O from agglomeration. Comparisons of the catalytic reactivity of Cu<SUB>2</SUB>O particles decorated with Co<SUB>3</SUB>O<SUB>4</SUB> nanoparticles of different sizes and shapes in terms of amounts and rates of hydrogen evolved by AB hydrolysis indicated that the size of Co<SUB>3</SUB>O<SUB>4</SUB> nanoparticles is more important than the shape to exhibit high catalytic reactivity.</p> <P>Graphic Abstract</P><P>Hydrogen evolution from ammonia borane by hydrolysis has been conducted with Cu<SUB>2</SUB>O particles covered with Co<SUB>3</SUB>O<SUB>4</SUB> nanoparticles. <img src='http://pubs.rsc.org/ej/EE/2012/c1ee02639a/c1ee02639a-ga.gif'> </P>

LaCoO₃ acting as an efficient and robust catalyst for photocatalytic water oxidation with persulfate

Yamada, Yusuke,Yano, Kentaro,Hong, Dachao,Fukuzumi, Shunichi The Royal Society of Chemistry 2012 Physical chemistry chemical physics Vol.14 No.16

<P>Cobalt-containing metal oxides [perovskites (LaCoO<SUB>3</SUB>, NdCoO<SUB>3</SUB>, YCoO<SUB>3</SUB>, La<SUB>0.7</SUB>Sr<SUB>0.3</SUB>CoO<SUB>3</SUB>), spinel (Co<SUB>3</SUB>O<SUB>4</SUB>) and wolframite (CoWO<SUB>4</SUB>)] have been examined as catalysts for photocatalytic water oxidation with Na<SUB>2</SUB>S<SUB>2</SUB>O<SUB>8</SUB> and [Ru(bpy)<SUB>3</SUB>]<SUP>2+</SUP> as an electron acceptor and a photosensitizer, respectively. Catalysts with the perovskite structure exhibited higher catalytic activity as compared with the catalysts with the spinel and wolframite structures. LaCoO<SUB>3</SUB>, which stabilizes Co(<SMALL>III</SMALL>) species in the perovskite structure, exhibited the highest catalytic activity in the photocatalytic water oxidation compared with CoWO<SUB>4</SUB>, Co<SUB>3</SUB>O<SUB>4</SUB> and La<SUB>0.7</SUB>Sr<SUB>0.3</SUB>CoO<SUB>3</SUB> which contain Co(<SMALL>II</SMALL>) or Co(<SMALL>IV</SMALL>) species in the matrices. The high catalytic reactivity of LaCoO<SUB>3</SUB> possessing perovskite structure was maintained in NdCoO<SUB>3</SUB> and YCoO<SUB>3</SUB> which exclusively contain Co(<SMALL>III</SMALL>) species. Thus, the catalytic activity of Co ions can be controlled by the additional metal ions, which leads to development of highly reactive and robust catalysts for the photocatalytic water oxidation.</P> <P>Graphic Abstract</P><P>Co-containing metal oxides were used as catalysts for photocatalytic water oxidation. Among them LaCoO<SUB>3</SUB> exhibited the highest catalytic activity, upon being used repeatedly without losing the catalytic activity. <IMG SRC='http://pubs.rsc.org/services/images/RSCpubs.ePlatform.Service.FreeContent.ImageService.svc/ImageService/image/GA?id=c2cp00022a'> </P>

Fatigue Strength of Fillet Welded Joint subjected to Plate Bending

Biehn Baik,Kentaro Yamada,Toshiyuki Ishikawa 한국강구조학회 2008 International Journal of Steel Structures Vol.8 No.3

Fatigue tests have been carried out on three types of non load-carrying fillet welded joint subjected plate bending, such as single-side fillet welded joint, T-shaped fillet welded joint and cruciform fillet welded joint. Fatigue failure of each welded joint has been demonstrated. The test results show that fatigue crack forms flat semi-ellipse during crack propagation and propagates to about 80% of plate thickness before failure. The fatigue strength and life recorded under bending test have been examined and compared with the previous results obtained by tension test. The fatigue strength of the fillet welded joint under bending is higher than that of the welded joint under tension. Fatigue tests have been carried out on three types of non load-carrying fillet welded joint subjected plate bending, such as single-side fillet welded joint, T-shaped fillet welded joint and cruciform fillet welded joint. Fatigue failure of each welded joint has been demonstrated. The test results show that fatigue crack forms flat semi-ellipse during crack propagation and propagates to about 80% of plate thickness before failure. The fatigue strength and life recorded under bending test have been examined and compared with the previous results obtained by tension test. The fatigue strength of the fillet welded joint under bending is higher than that of the welded joint under tension.

INSULITIS AND DIABETES MELLITUS

쿄헤이 나나카,켄타로 야마다,토시아키 하나후사,히로유키 토요시마,미쯔요시 나므바,세이치로 타루이 대한당뇨병학회 1981 Diabetes and Metabolism Journal Vol.6 No.1

한국과 일본 된장 중의 sodium 과 potassium 함량에 관한 연구

김천호,김자헌태랑,김전상지,각야맹,회전구인자,산전행이 한국식생활문화학회 1993 韓國食生活文化學會誌 Vol.8 No.1

된장은 한국과 일본의 식생활상 중요한 전통식품이나 10∼20%의 비교적 높은 염분함량으로 건강상 또는 여러가지 질병의 원인이 되고 있다고 보고 있다. 그러나 근래에는 Na함량 뿐만이 아니라 K함량과의 比도 중요하다고 보고 있어서 본 연구에서는 한국과 일본 된장들의 Na, K, NaCl함량과 동시에 Na/K比를 측정하고 양국간의 비교도 하였기에 보고한다. 한국의 시판 된장과 가내제품의 Na의 평균함량은 각각 4181.3㎎/100g, 6015.6㎎/100g 이고 일본에 있어서는 5082㎎/100g, 5890.6㎎/100g이다. 한국의 시판 된장과 가내제품의 K의 평균함량은 각각 595.8㎎/100g, 331.3㎎/100g 이고 일본에 있어서는 365.4㎎/100g, 381.3㎎/100g이다. 한국의 시판 된장과 가내제품의 NaCl의 평균함량은 각각 10.62%, 15.28%이고 일본에 있어서는 12.91%, 14.96%이다. 한국의 시판 된장과 가내제품의 Na/K比의 평균치는 각각 7.25, 21.54이고 일본에 있어서는 14.42, 16.14이다. 이상의 결과에서 예상과는 달리 한국의 시판 된장이 가내제품에 비해서 NaCl양이 적고 그외에도 Na양과 Na/K比에서도 다른 제품들에 비하여 낮으므로서 영양상 유리함을 나타냈다. We obtained the following results from determination of the sodium and potassium content contained in Denjang made in Korea and Japan. The mean sodium content of commercial denjang and home made denjang made in Korea and those of Japan are 4181.3㎎/100g, 6015.6㎎/100g and 5082.5㎎/100g, 5890.6㎎/100g, respectively. The mean potassium content of commercial denjang and home made denjang made in Korea and those of Japan are 595.8㎎/100g, 331.3㎎/100g and 365.4㎎/100g, 381.3㎎/100g, respectively. The mean NaCl concentration of commercial denjang and home made denjang made in Korea and those of Japan are 10.62%, 15.28% and 12.91%, 14.96% respectively. The mean Na/K ratios of commercial denjang and home made denjang made in Korea and those of Japan are 7.25, 21.54 and 14.42, 16.14 respectively.

Prevalence of Diffuse Idiopathic Skeletal Hyperostosis in Patients with Spinal Disorders

Hiromitsu Toyoda,Hidetomi Terai,Kentaro Yamada,Akinobu Suzuki,Sho Dohzono,Tomiya Matsumoto,Hiroaki Nakamura 대한척추외과학회 2017 Asian Spine Journal Vol.11 No.1

Study Design: Retrospective cohort study. Purpose: The purpose of this study was to evaluate the prevalence of diffuse idiopathic skeletal hyperostosis (DISH) in patients with spinal diseases determined by roentgen images of the whole spine. Overview of Literature: Although several studies have investigated the prevalence of DISH in healthy subjects, no detailed data have been reported on the prevalence of DISH in patients with degenerative spinal disorders. Methods: Standing whole-spine roentgen images of 345 consecutive patients who underwent surgery in our hospital were obtained. Patients aged <18 years or with congenital spinal disease, metastatic spinal tumors, or inflammatory spinal disease were excluded. In total, 281 patients were eligible for inclusion. The presence of DISH was assessed according to Resnick’s criteria and Mata’s scoring system. The prevalence, location, and numbers of fused vertebral bodies of DISH were recorded. Results: DISH was present in 25.6% of patients (72/281). The prevalence of DISH in the 41–49, 50–59, 60–69, 70–79, and ≥80 year age groups was 8.3% (2/24), 9.8% (5/51), 16.0% (12/75), 49.5% (48/97), and 33.3% (4/12), respectively; the prevalence increased with age. The average number of fused vertebral bodies was 7.5. More than 80% of DISH was located from T7 to T11, and more than 95% of DISH was located at T9/10. Patients with DISH were significantly older (71.1 years vs. 60.9 years, p <0.05), and men were more likely to have DISH than women (p <0.05). Conclusions: In patients with degenerative spinal diseases with DISH, fused vertebrae were found most frequently in the lower thoracic spine, and their prevalence increased with age. DISH may be an age-related skeletal disorder with a higher overall prevalence in patients with spinal disorders than that in healthy subjects.

Can Conventional Magnetic Resonance Imaging Substitute Three-Dimensional Magnetic Resonance Imaging in the Diagnosis of Lumbar Foraminal Stenosis?

Hasib Maruf Mohammad,Yamada Kentaro,Hoshino Masatoshi,Yamada Eiji,Tamai Koji,Takahashi Shinji,Suzuki Akinobu,Toyoda Hiromitsu,Terai Hidetomi,Nakamura Hiroaki 대한척추외과학회 2021 Asian Spine Journal Vol.15 No.4

Study Design: Retrospective radiological comparative design.Purpose: To investigate whether conventional magnetic resonance imaging (MRI) could substitute three-dimensional (3D)-MRI for the calculation of the foraminal stenotic ratio (FSR) and clarification of which patients can be assessed more accurately using 3D-MRI.Overview of Literature: Previous studies have indicated that 3D-MRI is useful for diagnosing lumbar foraminal stenosis. The FSR obtained using 3D-MRI, described as the ratio of stenosis length, characterized by perineural fat obliteration, to the length of the entire foramen, could indicate the stenosis severity; however, this method is time-consuming and expensive. The FSR also can be calculated using conventional MRI.Methods: We investigated 154 foramina at L5–S1 in 77 patients. All the patients had degenerative lumbar disorders and had undergone both conventional MRI and 3D-MRI during the same visit. Differences between the FSRs calculated from conventional and 3D-MRI reconstructions and any correlations with the plain radiography findings were assessed.Results: In foramina that had a FSR of <50% on conventional MRI, the difference between the FSR obtained using conventional MRI and 3D-MRI was 5.1%, with a correlation coefficient of 0.777. For foramina with a FSR ≥50% on conventional MRI, the difference was 20.2%, with a correlation coefficient of 0.54. FSR obtained using 3D-MRI was significantly greater in patients who required surgery than in those who were successfully treated with conservative methods (88% and 42%, respectively). Segments with spondylolisthesis or lateral wedging showed higher FSRs than those without these conditions on both types of MRI.Conclusions: FSRs <50% obtained using conventional MRI were sufficiently reliable; however, the results were inaccurate for FSRs ≥50%. Patients with high FSRs on 3D-MRI were more likely to require surgical treatment. Therefore, 3D-MRI is recommended in patients with suspected stenosis detected using conventional MRI or plain radiographs.