2015 VOL.70 NO.8

  Special Reports

Storage Products as Social Infrastructure in Era of Big Data

Toshiba Storage Products Contributing to Comfortable Lifestyles and Realization of Smart Communities
SATO Hiroyuki

Trends in Storage Product Technologies and Toshiba's Approach
YANAGI Shigenori / OHSHIMA Shigeo / ITO Jun
Toshiba has remained at the forefront of the storage industry for more than 40 years and offers a wide range of storage technologies, including hard disk drives (HDDs), NAND flash memories, and solid-state drives (SSDs), as well as storage solutions applying these technologies. In the present era, often referred to as the "big data era," digital technologies are showing unprecedented expansion and storage products have become one of the most vital components of society.
We will continue to support the broad spectrum of requirements for storage products and solutions by developing and implementing various technologies to improve device storage capacity, processing performance, reliability, and availability.

"KVDrive" Internet Protocol Drive for Object Storage Systems
TANAKA Shingo / GOTO Masataka / Philip KUFELDT
Object storage, a new storage system that enables large-scale storage systems to be constructed and managed at low cost, has recently been spreading in response to the explosive growth of digital data. Current object storage systems have several issues, however, including the need for a large number of servers when the system is enlarged due to its immature architecture, which relies on currently existing hardware and software.
Toshiba has developed the "KVDrive," an Internet Protocol (IP) drive storage system, in order to solve these issues. With the KVDrive, the need for a large number of servers is eliminated and the software architecture is simplified due to (1) the adoption of an architecture that allows direct access from clients, and (2) a key-value (KV) application programming interface (API). These features make it possible to realize a high-performance system with lower total cost of ownership (TCO) using the KVDrive.

Data-Centric Architecture to Realize Ultra-High-Speed Data Processing for Large-Scale Parallel and Distributed Systems
With the continuing increase in the volumes of data and complexity of data processing handled by facilities in both the private and public sectors, large-scale parallel and distributed systems, which can process data distributed to a large number of computers in parallel, are necessary to deal with large volumes of diverse data at high speed. However, typical parallel and distributed systems require a number of processes such as moving or preprocessing of the data in addition to the actual data processing, making it difficult to achieve the desired data processing speed.
To resolve this issue, Toshiba has devised a new computer platform for ultra-high-speed data processing utilizing NAND flash memories. By adopting a data-centric architecture incorporating node controllers equipped with a network port, the new platform realizes excellent scale-out characteristics and high-speed data processing performance as well as sufficient reliability and availability to handle enterprise applications. It is expected to be utilized as a platform for big data analysis that requires high-speed processing of large volumes of data.

SSD Series for Enterprise Use with Configurable Specifications to Flexibly Accommodate Applications
MORO Hiroyuki / KANEKO Atsushi
The use of solid-state drives (SSD) utilizing NAND flash memory is rapidly expanding in the field of cloud computing, which is highly dependent on enterprise servers and storage devices. Accompanying the dissemination of SSDs, their characteristics have become widely known and users' requirements have diversified, with priority being placed on specific features such as lower bit cost, higher read/write performance, larger capacity, higher endurance, or other characteristics.
Taking this trend into consideration, Toshiba has developed a new SSD series that not only provides improved performance, but also allows its specifications to be configured to accommodate the user's applications.

Single-Package SSD and Ultra-Small SSD Module Utilizing PCI Express(†) Interface
MURAKAMI Katsuya / NAGAI Koichi / TANIMOTO Akira
The transition of storage products from hard disk drives (HDDs) to solid-state drives (SSDs) has accelerated with the widespread dissemination of thin and light mobile PCs and tablets. Although HDD-compatible form factors were used at the initial stage of introducing SSDs, new SSD-specific small form factors are also now in use.
In response to the demand for lightweight storage products with a smaller form factor, Toshiba has developed a single-package SSD incorporating NAND flash memory chips and an SSD controller in a package with dimensions of 16 × 20 × 1.65 mm as the world's first single-package SSD with a PCI Express(†) interface. We have also developed an ultra-small card-edge type detachable SSD module containing the single-package SSD and a DC/DC converter with a size of 22 × 30 mm as the world's smallest SSD module with a PCI Express(†) interface.

2.5-inch HDD with World's Highest Areal Recording Density of 1 Tbit/in2
NAKA Hiroyuki / ABE Takao
Toshiba has developed the MQ03ABB300 four-platter 2.5-inch hard disk drive (HDD) with a capacity of 3 Tbytes, the largest capacity in the market for HDDs with a 15 mm height form factor. This was realized by achieving the world's highest areal recording density of 1 Tbit/in2 and improving the formatting efficiency.
In order to attain such a high areal recording density, we developed the following technologies: a magnetic head equipped with dual heaters introduced for the first time in our 2.5-inch HDDs to reduce magnetic head spacing, reduction of the disk magnetic cluster size to improve the signal-to-noise ratio (SNR), an advanced channel technology to enhance error correction capability, and dual-stage suspension (DSA) to improve the head positioning accuracy. Furthermore, the adoption of zone servo technology for the first time in our 2.5-inch HDDs to improve formatting efficiency also contributed to the achievement of large capacity.

Shingled Magnetic Recording Technologies for Large-Capacity Hard Disk Drives
The information infrastructure society has been undergoing further major changes in recent years. Whereas most digital data were formerly created by individuals using PCs, the progress of social networks has led to the generation of huge volumes of data on a daily basis from smartphones and other portable terminals. Furthermore, the data produced by various sensors in the Internet of Things (IoT) has also been rapidly increasing. The total volume of data generated in the world in 2020 is projected to reach 44 zettabytes (ZB; 1 ZB = 1021 bytes), 10 times the volume in 2013. Larger capacity hard disk drives (HDDs) are therefore required in the market to store these huge volumes of data.
To address this demand, Toshiba has been developing shingled magnetic recording (SMR) technologies. SMR HDD record data in a narrower track pitch than conventional HDDs by overwriting a part of the adjacent track that has been recorded, like shingling a roof, using a write head of conventional size. We are working to realize new technologies for SMR that strengthen its advantages and compensate for its weak points.


  Feature Articles

Automatic Volumetric Measurement of Lung Nodules in CT Images Based on Image Segmentation Technology
YAGUCHI Atsushi / OKAZAKI Tomoya / AOYAGI Kota
In the diagnosis and follow-up of lung cancer by means of computed tomography (CT) images, it is important to assess lung nodule size and its long-term changes. The nodule size is conventionally measured manually by determining its maximum and minimum diameters on two-dimensional CT image slices. However, problems regarding the accuracy and reproducibility of such manual measurements as well as the high burden on the doctor are critical issues. Furthermore, of the two main compositions of lung nodules, namely, the solid and ground glass opacity (GGO) types, it is particularly difficult to measure the size of the GGO type due to its low image contrast and indistinct boundary.
To address these issues, Toshiba and Toshiba Medical Systems Corporation, in cooperation with Kobe University, have developed a novel technology to achieve automatic volumetric measurement of lung nodules, not only of the solid type but also the GGO type, by applying an image segmentation technology. Experiments on this technology using synthetic nodules have quantitatively verified that it achieves lower volumetric measurement errors for both solid and GGO nodules compared with other studies under similar conditions.

LED Bulb Type Module Highly Compatible with Traditional Incandescent Bulbs
KATO Mitsuaki / OHNO Hiroshi / TSUDA Ryoji
With the improvement in efficiency of light-emitting diodes (LEDs), the replacement of traditional incandescent bulbs by LED bulbs has been accelerating. In order to promote the wider dissemination of LED bulbs, all of their specifications, including not only their luminance and light distribution but also their light spectrum, light-emitting position, transparency, size, and weight, need to be equivalent or superior to those of incandescent bulbs, particularly in the European market. However, the trade-off relationships among these characteristics are a critical issue.
Toshiba has now developed an LED bulb type module incorporating the following technologies to reproduce such characteristics of incandescent bulbs: (1) a pole type heat radiator that creates a glass globe over the entire surface and cools the LED through heat radiation and natural convection without any nontransparent heat sink; (2) a light guide that achieves light emission in the center of the globe with wide light distribution through total internal reflection and scattering; and (3) a white LED that realizes natural white light emission, consisting of a purple LED with a combination of phosphors based on red-green-blue (RGB). This module has been employed as a replacement for incandescent bulbs by a prominent European lighting designer since April 2015.

Plasma Analysis Technologies for PM2.5 Electric Particle Collectors to Improve Performance of Room Air Conditioners
UI Akio / SATO Yosuke / SEKI Yusuke
Attention has been focused in recent years on the adverse effects of particulate matter of 2.5 µm or less in diameter (PM2.5) on the human body, particularly on the respiratory system. There is consequently an increasing need for indoor air purification and particle collection technologies.
To address this issue, Toshiba has developed and released the only room air conditioners in Japan that comply with the HD-128 purification standard for PM2.5 specified by the Japan Electrical Manufacturers' Association (JEMA). We have now developed plasma analysis technologies for the electric particle collectors of these air conditioners, which employ plasma air purification, by combining numerical analyses for two phenomena–the plasma-induced charging of particles and the collection of charged particles–aimed at strengthening particle collection performance. Through optimization of parameters including the applied voltage and the shape of the electrodes based on the results of these analyses, the SDR series room air conditioners released in 2015 achieve double the particle collection performance specified by the HD-128 standard.

Simulation Technology for Evaluation of Current Collapse in GaN Power Devices
KIKUCHI Takuo / ISHIKAWA Satoshi / NAKA Toshiyuki
Due to the superior electrical characteristics of gallium nitride (GaN) power devices compared with those of currently available silicon (Si) devices, demand has been growing for the early application of GaN power devices to power conversion equipment. However, the development of GaN power devices with the desired performance is hindered by technical issues associated with increased on-resistance as a result of current collapse caused by crystal defects and interface traps in these devices. In this situation, there is a need for simulation technologies that can predict on-resistance degradation over time as well as the basic transistor characteristics in the design phase.
Toshiba has developed a simulation technology to precisely and quantitatively evaluate the on-resistance degradation of GaN power devices by modeling crystal defects and interface traps in a device, which vary according to the manufacturing process, based on measured results using a test element group (TEG) pattern with the same device structure. This technology makes it possible to detect the degradation of device characteristics and failure earlier and with greater certainty, thereby shortening the device development period.

Development of Monitoring Instruments for Use in Event of Severe Accident at Nuclear Power Plant
KURODA Hidehiko / OKAZAKI Koki / ISODA Koichiro
With the aim of further enhancing safety measures in the event of a severe accident at a nuclear power plant, Toshiba has been developing monitoring instruments for reactor pressure vessels (RPV) and primary containment vessels (PCV). These include an instrument for monitoring the water level in the RPV and instruments for monitoring the hydrogen concentration and radiation dose rate in the PCV as well as the water level in the PCV in the case of feeding coolant to the PCV in a severe accident situation.
From the results of functional tests using prototype sensors for these monitoring instruments under severe conditions of high temperature, high pressure, and steam, we have confirmed that these sensors can detect water level, hydrogen concentration, and radiation dose rate, respectively, with high accuracy. Moreover, through experiments under conditions simulating the environment of a severe accident, we have confirmed that each of the sensors satisfies the respective requirement specifications. The monitoring instruments are durable and reliable, and their measurement principles are simple. We are now planning detailed designs toward their application to nuclear power plants in the future.

Introduction into Brunei of SCADA/EMS System Utilizing Common Platform for Overseas Markets
AOKI Yuri / MAKINO Shigeyuki
Accompanying the rising awareness of the need to lessen the burden on the environment and reduce carbon dioxide (CO2) emissions in recent years, efforts are being made to improve the efficiency of power grids in electric power systems and develop new technologies for smart grids, renewable energy sources, battery energy storage systems, and so on. Both visualization of electricity consumption and introduction of real-time monitoring and control systems for power grids are the first step toward the realization of a smart grid, which is a next-generation power grid that ensures optimal power supply by monitoring and controlling electric power from both the demand side and supply side.
Toshiba has developed a supervisory control and data acquisition (SCADA) system and energy management system (EMS) utilizing a newly developed common platform for power grid control and monitoring systems in overseas markets. We have supplied this SCADA/EMS system to the Department of Electrical Services (DES), the public power utility in Brunei, in order to facilitate real-time monitoring and control of its power grid.

DC Switchgear for Railway Substations in Compliance with JIS/IEC Standards
OTSUJI Koji / KANDA Koji / IKEBE Takayuki
DC switchgears, one of the key components of an electric railway substation, shut off the fault current and immediately disconnect the fault section from other operational sections in the event of a problem. The construction of electric railway systems is expected to further expand throughout the world in the coming years, particularly in developing countries, resulting in increased demand for DC switchgears.
In response to this trend, Toshiba has developed the HS6 type DC switchgear that has been adapted to meet global standards based on the technological know-how and experience cultivated through the development of products for the Japanese market. The HS6 type DC switchgear complies with the JIS (Japanese Industrial Standards) E 2501 and the IEC (International Electrotechnical Commission) 61992 standards. Its volume has been reduced by almost 33% compared with our conventional HS1 type DC switchgear due to simplification of the control circuit through the use of multifunctional protection relays and newly developed control boards for the circuit breakers and disconnectors. It also offers enhanced functions due to improvements in the electrical and structural design.


  Frontiers of  Research & Development

Improvement of Genotyping Performance Using Machine Learning

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