We have developed a high-throughput recording and playback method for full-specification 8K SHV video whose data rate is up to 2400 MB/s. The method fully exploits hardware with a specific design for handling large amounts of data, sequential transfer, and frame unit random reads including fast-forward, rewind and jogshuttle. The data transfer speed is more than 3000 MB/s when using SSD striping. Steady recording and playback, including frame unit random reads, were demonstrated on an 8K SHV recorder and player.

View full abstract

In the present study, feasibility of magnetic vortex core (VC) polarity as a binary information carrier has been investigated by micromagnetics simulations. Both of the read and write operation were carried out with current induced pulsed microwave fields, but different amplitude, generated with a pair of orthogonally overlaid conductors. Asymmetric resonance properties of the VC rotational motion against the circularly polarized microwave fields were converted to the inductive voltage. Overwrite of the VC polarization was also performed by utilizing the asymmetric VC switching property. Structural parameters for proposed device architecture were systematically optimized for efficient memory operation. Successive read (write) operation was demonstrated with pulsed alternative currents of 1.18 GHz frequency, 4.2 ns duration (5 periods) and 0.6 mA (1.2 mA) amplitude.

View full abstract

Tape systems experience large speed variations compared to disk systems, and therefore, it is necessary to design a stable timing recovery scheme that can operate under a low signal-to-noise ratio (SNR) condition. In such low SNR scenarios, the decision error made by the detector often results in a phase-locked loop circuit losing track of the correct signal. This phenomenon is often called the loss-of-lock (LOL) phenomenon. In order to mitigate the LOL issue, soft information from the soft output Viterbi algorithm decoder is used to control the feedback in the timing recovery loop. Therefore, a timing recovery method for high-density tape storage system is studied in this paper. By applying this new method to the read back signal from the actual tape drive, it is verified that the negative effect of misdetection due to unreliable decisions from the detector can be compensated, with only a minor increase in implementation complexity.

View full abstract

We have developed advanced magnetic tapes using fine barium ferrite particles. The magnetic particle volume of barium ferrite in the tapes is 1600 nm³. The perpendicular squareness ratio, surface roughness (obtained by optical interferometry), and ten-point average roughness (obtained by atomic force microscopy) of these tapes is 0.87, 0.9 nm, and 27 nm, respectively. The tapes show an areal density of 123 Gb/in², corresponding to a capacity of 220 TB, achieved by a combination of advanced drive technologies.

View full abstract

This paper explores how electronic paper should be used in office work in the future. Nine participants used an A4-size electronic paper device in their actual work. The results revealed that the electronic paper device is easy to handle as a device and it was well suited to support reading and writing activities which includes frequent hand-using actions such as moving, holding, and pointing the device. However, participants felt difficulty in page navigation and overviewing documents and these features are inevitable to support document-related work in the office. To resolve this, we suggest that electronic paper should focus on its strengths and make other devices compensate for its weaknesses. In this framework, multiple devices support a single activity together by making use of strengths of each device. We also discuss three application domains: active reading, collaborative work using documents, and note-taking in the field.

View full abstract

The deteriorations of carrier mobility of organic thin film transistors after immersing into various solvents containing fluorine were investigated. The deteriorations showed the correlation with the fluorophilicity, the partition ratio between solvents containing fluorine and without fluorine. The fluorophilicity will be a useful parameter for screening the process solvent.

View full abstract

The ZnO nanorods on aluminum doped ZnO thin films were synthesized by both chemical bath deposition and multi-annealing methods. The ZnO nanorods were vertically aligned on aluminum doped ZnO substrates in both methods, which was attributed to the good crystallinity and crystal growth direction of underneath aluminum doped ZnO film. A high transmittance of 75% was obtained from both of the synthesized ZnO nanorods. The photoluminescence of ZnO nanorods obtained by multi-annealing method had strong bluegreen emission. However, a strong orange-red emission was observed from ZnO nanorods by chemical bath deposition.

View full abstract

Recently, the Fisher vector representation of local features has attracted much attention because of its effectiveness in both image classification and image retrieval. Another trend in the area of image retrieval is the use of binary features such as ORB, FREAK, and BRISK. Considering the significant performance improvement for accuracy in both image classification and retrieval by the Fisher vector of continuous feature descriptors, if the Fisher vector were also to be applied to binary features, we would receive similar benefits in binary feature based image retrieval and classification. In this paper, we derive the closed-form approximation of the Fisher vector of binary features modeled by the Bernoulli mixture model. We also propose accelerating the Fisher vector by using the approximate value of posterior probability. Experiments show that the Fisher vector representation significantly improves the accuracy of image retrieval compared with a bag of binary words approach.

View full abstract

In this paper, a fully automatic gastric cancer risk classification method with the aim of constructing a computer-aided diagnosis (CAD) system is presented. Two-stage classification is used in the proposed method for determining gastric cancer risk. In the first stage, the proposed method detects H. pylori-infected patients, i.e., detection of patients who have gastric cancer risk, and the proposed method classifies the level of gastric cancer risk, i.e., high or low, from H. pylori-infected patients in the second stage. In each stage, we derive new image features that are closely related to values of blood examination via kernel canonical correlation analysis. The introduction of these new image features provides classification improvement in each stage, and it is the main contribution of this paper. Consequently, accurate classification becomes feasible by the proposed method. Experimental results obtained by applying the proposed method to real X-ray images show that our method outperforms several comparative methods.

View full abstract

We have devised multi-viewpoint robotic cameras for capturing multi-viewpoint images of subjects moving in 3D space with panning shots and zoom-in shots. The camera operator instructs a robotic camera to fix its gaze point at an arbitrary position in 3D space and other robotic cameras automatically follow it as their gaze point. The operator can then capture multi-viewpoint images by fixing the gaze point on the subject position. Bullet time and integral 3D imagery are generated from the images shot by the cameras. Bullet time is generated by using a virtual camera control with a projective transformation to make the viewpoints change smoothly. Integral 3D images are generated by converting a 3D model of a subject created using the depth estimation method into elemental images. In experiments, robotic cameras were able to capture multi-viewpoint images of a sports player moving in 3D space and bullet time and integral 3D imagery were generated from these images. Furthermore, these robotic cameras were used to generate bullet time in a live broadcast of a figure skating competition. In particular, bullet time was used to show the skaters' jumps in instant replays right after each performance.

View full abstract

In this paper, a compact UWB dual-polarized antenna with improved co-to-cross-polarization ratio is proposed. This antenna is fed by two orthogonal tapered CPW lines to achieve dual-polarization operation. To enhance the polarization purity and the isolation level between the antenna's ports, a new technique is proposed. The detailed design, as well as the analysis of the obtained results, are presented and discussed, which revealed that the proposed antenna is matched over the entire UWB band with good isolation level between its ports of 20dB and high co-to-cross polarization ratio of more than 20dB. With these features, the proposed antenna is an optimized candidate for media applications.

View full abstract

In this paper, we present the design of a new ultra-wideband (UWB) frequency selective surface (FSS) based antenna, by using a wide stop-band FSS as a backing reflector for an UWB monopole antenna. A new single layer FSS, with UWB stop-band response and a reflection phase varies linearly with frequency, is firstly designed and thereafter, it is integrated with an UWB electric monopole. The studies of the behavior of the proposed antenna reveal that a unidirectional radiation with a quasi-constant gain of an average of 9dBi and a compact profile of λ/10 are achieved. The features of the proposed UWB FSS and its based antenna make them good candidates for integration with low profile broadband printed circuits and UWB applications.

View full abstract

This paper discusses a multipath compensation technique for body area network systems using a pulse-based ultra-wideband method. In the paper, a combined RAKE reception and multi-band template pulse is proposed. RAKE reception is an effective time domain multipath compensation technique. The multi-band template pulses can be used to control the powers of the sub-band pulses and adaptively approximate the received signals. The normalized root mean square error between the ideal received signal and the template pulse is then evaluated. The performance improves when using an iterative weight determination scheme for selective RAKE reception and the multi-band pulses, because the template pulse correlation in each RAKE branch can be reduced and the frequency-selective fading can be compensated. The bit error rate (BER) performance is also evaluated. The results show that the BER is improved and that the number of RAKE branches can be reduced when using the proposed scheme.

View full abstract