Refine your search:     
Report No.
 - 
Search Results: Records 1-10 displayed on this page of 10
  • 1

Presentation/Publication Type

Initialising ...

Refine

Journal/Book Title

Initialising ...

Meeting title

Initialising ...

First Author

Initialising ...

Keyword

Initialising ...

Language

Initialising ...

Publication Year

Initialising ...

Held year of conference

Initialising ...

Save select records

Journal Articles

Origin of magnetovolume effect in a cobaltite

Miao, P.*; Tan, Z.*; Lee, S. H.*; Ishikawa, Yoshihisa*; Torii, Shuki*; Yonemura, Masao*; Koda, Akihiro*; Komatsu, Kazuki*; Machida, Shinichi*; Sano, Asami; et al.

Physical Review B, 103(9), p.094302_1 - 094302_18, 2021/03

 Times Cited Count:0 Percentile:0(Materials Science, Multidisciplinary)

The layered perovskite PrBaCo$$_{2}$$O$$_{5.5}$$ demonstrates a strong negative thermal expansion (NTE) which holds potential for being fabricated into composites with zero thermal expansion. The NTE was found to be intimately associated with the spontaneous magnetic ordering, known as magneto-volume effect (MVE). Here we report with compelling evidences that the continuous-like MVE in PrBaCo$$_{2}$$O$$_{5.5}$$ is intrinsically of discontinuous character, originating from an magnetoelectric transition from an antiferromagnetic insulating large-volume (AFILV) phase to a ferromagnetic less-insulating small-volume (FLISV) phase. Furthermore, the magnetoelectric effect (ME) shows high sensitivity to multiple external stimuli such as temperature, carrier doping, hydrostatic pressure, magnetic field etc. In contrast to the well-known ME such as colossal magnetoresistance and multi-ferroic effect which involve symmetry breaking of crystal structure, the ME in the cobaltite is purely isostructural. Our discovery provides a new path way to realizing the ME as well as the NTE, which may find applications in new techniques.

Journal Articles

Visualization system for large-scale network data; A Large scale data capture technique

Miyamura, Hiroko; Ozahata, Satoshi*; Nakao, Akihiro*; Kawashima, Konosuke*; Teshima, Naoya*; Suzuki, Yoshio; Takemiya, Hiroshi

Zen NUA C&C Shisutemu Yuzakai Heisei-22-Nendo Rombunshu (CD-ROM), 14 Pages, 2011/02

Recently, construction of large-scale distributed file systems has become easier because of reduced hardware costs and the availability of large hard disks and faster networks. However, if the sizes and/or numbers become too large, occasionally even the data server manager cannot control the storage situation of the files. Therefore, we propose the concept of adaptive network graph display, in which the graph style can be changed according to the details of what the user details is observing, and construct a visualization system based on this concept. When observing data globally, the proposed system selectively displays information based on the clustering result, and when observing data locally, the system displays detailed information. This technique is a basic technology for computational science to achieve large-scale datasets handling and knowledge succession which is a problem in atomic energy related fields.

Journal Articles

Adaptive visualization for analyzing large-scale network datasets

Miyamura, Hiroko; Ozahata, Satoshi*; Nakao, Akihiro*; Kawashima, Konosuke*

Shingaku Giho, 110(190), p.103 - 108, 2010/09

In this paper, we propose a visualization technique for handling large-scale experiment datasets in distributed file system. Traditional network visualization techniques have problem that not all data can be displayed at the same time because the file-sharing network data is too large-scale. Therefore, we propose a concept of adaptive network graph display, in which the graph style can be changed according to the details of user's observation. We construct a visualization system based on this concept. When observing data globally, the proposed system selectively displays information based on the clustering result, and when observing data locally, the system displays detailed information. This technique is a basic technology for computational science to achieve large-scale datasets handling which is a problem in atomic energy related fields.

Journal Articles

A Network visualization system with interactive operations for important nodes discovery

Miyamura, Hiroko; Ozahata, Satoshi*; Nakao, Akihiro*; Kawashima, Konosuke*; Suzuki, Yoshio

Denki Gakkai Kenkyukai Shiryo, Sangyo Keisoku Seigyo Kenkyukai (IIC-10-85), p.27 - 32, 2010/03

We propose a network visualization system for a file-sharing network data-set. The network dataset consists of the information on nodes and links. As the number of links increases, the visualization of the network becomes challenging since the links usually cross over one another, which makes it hard to understand the structure of the network through the visualization. In order to present a network structure clearly and to identify keynodes that play important roles in the network, we propose a network visualization system. In this research, we propose additional techniques that support users searching the key node by using interactive functions such as filtering and node arranging.

Journal Articles

A Network visualization system focusing on important nodes

Miyamura, Hiroko; Ozahata, Satoshi*; Nakao, Akihiro*; Kawashima, Konosuke*; Suzuki, Yoshio

Shingaku Giho, 109(448), p.357 - 362, 2010/03

We propose a visualization system for file-sharing network data. The file-sharing networks have some problems, for example: the contents distribution of the copyright infringement files, an increase in the amount of traffic, and so on. To handle these problems, techniques for observing the network state and controlling the file sharing are proposed. In addition, the proposed techniques realize effective control by giving retrieval control to the key nodes, which are important roles in the file-sharing network.

Journal Articles

A Large scale network visualization for important nodes discovery

Miyamura, Hiroko; Ozahata, Satoshi*; Nakao, Akihiro*; Kawashima, Konosuke*; Suzuki, Yoshio

Shingaku Giho, 109(188), p.85 - 90, 2009/09

We propose a network visualization method for a large-scale file-sharing network dataset. The network dataset has nodes and links that represent the connection between two nodes. When the number of links is large, it is difficult to recognize the structure of the network data, because many links are crossed. In this context, for recognizing the structure and exploring the key nodes, we propose a link-less network visualization method using matrix based representation. In addition, we demonstrate the effectiveness of the proposed method by applying it to the file-sharing network log data.

Oral presentation

Fabrication and evaluation of light-emitting SiO$$_{2}$$ substrate co-implanted with Si and C ions

Kikuchi, Shusuke*; Umenyi, A. V.*; Inada, Kazuki*; Kawashima, Akihiro*; Noguchi, Katsuya*; Sasaki, Tomoyuki*; Miura, Kenta*; Hanaizumi, Osamu*; Yamamoto, Shunya; Kawaguchi, Kazuhiro; et al.

no journal, , 

Light emission around a wavelength ($$lambda$$) of 500 nm from SiO$$_{2}$$ substrates implanted with Si and C ions and annealed at 1100$$^{circ}$$C has been reported. In this report, we investigated photoluminescence (PL) properties of SiO$$_{2}$$ substrates implanted with Si and C ions and annealed at the lower temperature of 700$$^{circ}$$C. PL peaks by Si-ion implantation were observed around $$lambda$$ = 650 nm, and PL peaks by C-ion implantation were observed around $$lambda$$ = 450 nm from SiO$$_{2}$$ substrates annealed at 700$$^{circ}$$C. The PL peak wavelength became shorter by increasing the ratio of C to Si ions. Consequently, it was confirmed that it is possible to control the emission wavelength by the ratio of C to Si ions. Our samples showed typical light-emission though the annealing temperature was lower than the temperature reported by other groups.

Oral presentation

A Multilevel graph layout for analysing of large-scale network datasets

Miyamura, Hiroko; Yoshida, Masahiro*; Ozahata, Satoshi*; Takahashi, Shigeo*; Nakao, Akihiro*; Kawashima, Konosuke*

no journal, , 

We propose a multilevel graph layout technique for visualizing large scale network datasets. Large-scale datasets are said to be difficult to analyze and visualize. However, with our technique, the datasets can be displayed in multistep. For instance the outline of network dataset is shown first, and when focused on a certain region, the detailed information is shown as well. By using this technique, users can observe a large scale dataset from the outline to the detail seamlessly, and therefore this is valuable for the structural analysis of network datasets.

Oral presentation

Photoluminescence properties of light-emitting SiO$$_{2}$$ substrates implanted with Si and C ions

Inada, Kazuki*; Kawashima, Akihiro*; Kano, Keisuke*; Noguchi, Katsuya*; Miura, Kenta*; Hanaizumi, Osamu*; Yamamoto, Shunya; Kawaguchi, Kazuhiro*; Yoshikawa, Masahito

no journal, , 

It is reported that Si and C ions implanted SiO$$_{2}$$ substrates emit blue light. In this paper, we are studying photoluminescence (PL) properties of SiO$$_{2}$$ substrates implanted with Si and C ions on various conditions. Si and C ions were implanted into an SiO$$_{2}$$ substrate by using a 400-kV ion implanter at JAEA/Takasaki. The Si-ion implantation energy was 150 keV, and the implantation dose was $$sim$$5.0$$times$$10$$^{16}$$ ions/cm$$^{2}$$. The C-ion implantation energy was 75 keV, and the implantation dose was $$sim$$3.0$$times$$10$$^{16}$$ ions/cm$$^{2}$$. The samples were subsequently annealed at 700$$^{circ}$$C for 25 min in air, after 1000$$^{circ}$$C for 25 min in air. The results of PL measurements show that the PL peak wavelength became shorter by increasing the ratio of C ions to Si ions. Consequently, it was confirmed that the emission wavelength can be controlled by hanging the ratio of C and Si.

Oral presentation

Development of fabrication technique of optical functional devices by ion beam irradiation

Miura, Kenta*; Hanaizumi, Osamu*; Kada, Wataru*; Ozawa, Yusuke*; Inada, Kazuki*; Kubota, Atsushi*; Kawashima, Akihiro*; Sato, Takahiro; Ishii, Yasuyuki; Koka, Masashi; et al.

no journal, , 

no abstracts in English

10 (Records 1-10 displayed on this page)
  • 1