Yokohama Research Laboratory

Hitachi, Japan

Yokohama Research Laboratory

Hitachi, Japan

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Yoshikawa Y.,Hitachi Ltd. | Tada K.,Information and Telecommunication Systems Company | Furuya S.,Yokohama Research Laboratory | Koda K.,Information and Control Systems Company | Geerli,Global Business Promotion Center
Hitachi Review | Year: 2011

Overview: Successfully combining protection of the global environment with prosperous urban lifestyles that are secure and convenient is an important factor in ensuring the sustainability of cities. The social infrastructure that supports such a city is required not only to establish robust safety and security, it also needs to satisfy criteria such as enhancing urban value by overall optimization and reduction of total cost. To achieve this, parts of the social infrastructure like power, transport, and water which have been optimized independently in the past need to be comprehensively redesigned based on considerations such as environmental performance, customer service level, and operation and maintenance costs. This is one of the prerequisites for achieving what Hitachi calls "next-generation smart cities.".


Watanabe M.,Hitachi Ltd. | Onishi T.,Information and Control Systems Company | Omori T.,Information and Control Systems Company | Terada H.,Yokohama Research Laboratory | Inagaki K.,Hitachi Ltd.
Hitachi Review | Year: 2011

OVERVIEW: How to maintain the quality of electric power on the grid in terms of voltage and other parameters and ensure that equipment operates efficiently will be important considerations if large quantities of solar power generation are to be connected. In response, Hitachi is working on technology development with the aims of introducing equipment such as section switches with built-in sensors and advanced metering infrastructure, developing control equipment, and enhancing monitoring and control. In particular, research and development of SCADA system technologies and voltage control equipment that help maintain power quality on the grid are helping to speed up preliminary investigations into how to maintain power quality and minimize the cost of adapting the grid to cope when large amounts of photovoltaic and other distributed power resources are introduced, thereby helping achieve reductions in CO2 emissions.


Iijima K.,Yokohama Research Laboratory | Fukumoto T.,Yokohama Research Laboratory | Shimura A.,Yokohama Research Laboratory | Kato H.,Yokohama Research Laboratory | Hirasawa S.,Smart Design
Hitachi Review | Year: 2012

To supply public infrastructure systems that keep pace with changes in society, Hitachi is promoting the symbiosis autonomous decentralized concept, a system concept for achieving the sustainability of society as a whole while treating change as the norm. To turn this concept into reality, Hitachi is developing system development technologies that satisfy the requirements at the system planning, construction, and operation/evaluation phases. These consist of: (1) Social system modeling and simulation techniques that keep these systems in an optimal and stable condition by controlling the flow of information to stakeholders, (2) System renovation techniques for rebuilding systems without interrupting services by modeling the principles of the physical structures and phenomena that support public infrastructure services, and (3) Heterogeneous system cooperation techniques for achieving optimum operation across the entire system by dynamically linking together the different systems owned by a particular organization.


Accorsi R.,Albert Ludwigs University of Freiburg | Lowis L.,Albert Ludwigs University of Freiburg | Sato Y.,Yokohama Research Laboratory
Business and Information Systems Engineering | Year: 2011

A key problem in the deployment of large-scale, reliable cloud computing concerns the difficulty to certify the compliance of business processes operating in the cloud. Standard audit procedures such as SAS-70 and SAS-117 are hard to conduct for cloudbased processes. The paper proposes a novel approach to certify the compliance of business processes with regulatory requirements. The approach translates process models into their corresponding Petri net representations and checks them against requirements also expressed in this formalism. Being based on Petri nets, the approach provideswell-founded evidence on adherence and, in case of noncompliance, indicates the possible vulnerabilities. © Gabler Verlag 2011.


Nishiyama N.,HGST Japan Ltd. | Soga Y.,HGST Japan Ltd. | Contreras J.T.,HGST Inc | Wallash A.,HGST Inc | Nakamura S.,Yokohama Research Laboratory
IEEE Transactions on Magnetics | Year: 2013

Disk drives' high data rate frequencies now occupy the same radio-frequency (RF) signal frequency bands of wireless communication networks. RF signals invade into the disk enclosure (DE) through the hard disk drive's slots, which are created by the gap between the top cover and the base between screws. Poor immunity DE designs allow wireless RF signals to interfere with the low-amplitude read signal of the customer's data. It is important to find the invasion path of the RF signal interference, and to apply the countermeasure to improve RF immunity. To determine the best configurations for RF immunity from a slot to the read path, this paper compares the RF immunity among four kinds of signal-trace suspension configurations by two kinds of extrinsic RF coupling measurement methods. Analysis shows that proper ground routing of some signal return traces can significantly improve RF immunity, and electrostatic discharge protection. © 2013 IEEE.


Mizuno Y.,Information and Telecommunication Systems Company | Yano K.,Yokohama Research Laboratory | Okochi K.,Enterprise Systems | Mashita Y.,Information and Telecommunication Systems Company
Hitachi Review | Year: 2012

To achieve a well-balanced relationship between people and the Earth that can deliver a comfortable way of life in a low-carbon society, future public infrastructure will need to adapt to changes in the relationships between suppliers and consumers through new business models and by using information in ways it has not been used in the past. This will require new ways of using information; support for devices, applications, and other elements that have proliferated with the growing diversity of service providers; and that the systems underpinning public infrastructure are reliable and able to provide trouble-free operation over the long term. To achieve this, Hitachi is developing the common IT platforms needed by the systems that support the public infrastructure.


Harada K.,Yokohama Research Laboratory | Sato Y.,Yokohama Research Laboratory | Togashi Y.,Yokohama Research Laboratory
Annual SRII Global Conference, SRII | Year: 2012

A lot of information has recently been collected and the need to put it to secondary use is expanding. This is because a lot of useful knowledge is contained in it. There are always privacy concerns with the secondary use of personal information. k-anonymization is a tool that enables us to release personal information in a manner that is privacy-protected. In classical k-anonymization, side information, which is termed generalization hierarchies, is always needed. In addition, the quality of k-anonymized data has always been a central problem in the area because information loss is an inherent feature of anonymization. This paper proposes a new scheme in which generalization hierarchies are automatically constructed by input information. This scheme not only contributes to reducing the cost of operations for preparing side information, but also to increasing the quality of k-anonymization results. Experiments have demonstrated that k-anonymization with automatically constructed hierarchies sacrifices 38% less data (measured by information entropy) than that with complete binary trees (introduced as classically-used hierarchies). © 2012 IEEE.


Funato H.,Yokohama Research Laboratory | Suga T.,Yokohama Research Laboratory | Suhara M.,Tokyo Metroplitan University
IEEE International Symposium on Electromagnetic Compatibility | Year: 2013

A position/signal difference method for electric near-field measurements has been investigated and extended to a double position/signal difference method in order to independently extract the normal and tangential electric near-field components using two measurements at slightly different heights above the test object. A printed monopole probe was fabricated and used for electric near-field measurements above a microstrip line using the proposed method. In addition, full-wave electromagnetic simulations were carried out and the measured normal and tangential components were found to be in good agreement with the simulation results at 1 GHz. © 2013 IEEE.


Ishigami T.,Yokohama Research Laboratory | Tanaka Y.,Yokohama Research Laboratory | Homma H.,Yokohama Research Laboratory
Electrical Engineering in Japan (English translation of Denki Gakkai Ronbunshi) | Year: 2014

Aimed at providing small high-power motors with excellent efficiency, a motor stator with rectangular-wire lap windings and an automatic process for its production were developed. The structure of the windings, namely, two continuous "α-shaped" coils, and the coil-production method (involving simultaneous coil forming and coil insertion) enable mass production of this stator. The slot-fill rate for a prototype stator was 80.5%, and the total height of the coil ends was 60 mm to 72 mm. On the basis of the ratio of the sectional areas of two types of the motors, its efficiency was estimated to be 3.7% higher than the efficiencies of motor stators with round-wire concentric windings (at a rotation speed of 1000/min). In addition, the number of coil parts and the number of welding points were greatly reduced compared to those of a stator with segmented-coil wave windings. © 2014 Wiley Periodicals, Inc.


Shibuya H.,Yokohama Research Laboratory
Electronics and Communications in Japan | Year: 2016

An anomaly detection method based on multidimensional time-series sensor data and using normal state models has been developed. The local subspace classifier (LSC) method is employed to handle the various normal states and the fast LSC method is proposed to reduce the computation time. Clustering is utilized to reduce the amount of data when searching in the fast LSC (FLSC) method. The effectiveness of the FLSC method is confirmed against data from real equipment. The FLSC method is 1 to 10 times as fast as the LSC method. © 2016 Wiley Periodicals, Inc.

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