electric power laboratory department of electrical ......for example, sf 6, cf 3 i, co 2, n 2, o 2,...

1

Electric Power Laboratory

Department of Electrical

Engineering

Faculty of Engineering

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Research Topics Property Investigation of Gas by Pulse Laser-induced

Plasma Method

Mechanism for Surface Charge Decay on Dielectrics

Analyzing for discharge and plasma temperature

Barrier Discharge under Insulation Material with Steep Impulse Voltage

Influence of Particle Charge and Sparkover Discharge by using Laser under DC High Voltage

Breakdown Mechanism of very Thin Thickness Insulation Material

Prof. NISHIJIMA Kiyoto、Dr. SASAMOTO Ryo.

Electric Power Lab

www.***.co.jp

Property Investigation of Gas by Pulse Laser-Induced Plasma Method

In electrical insulation field

In discharge and plasma application field

In electric power applications, the gas insulation system

has widely been used.

For example, GIS (gas insulation system), GCB (gas

circuit breaker), ACB (air circuit breaker) and so on.

Recently, the discharge and plasma applications use

discharge or plasma at atmospheric pressure.

For example, surface treatment of semiconductor,

plasma jet and so on.

GIS

Surface

treatment

It is important to understand gas characteristics at atmospheric pressure because several gas

have widely been used. So, many researchers and engineers have researched the fundamental

parameters of several gas. However, these data are almost low pressure data because it is

difficult to measure these data at atmospheric pressure. Therefore, these measurement data at

atmospheric pressure are still insufficient.

However, we can measure these data by Pulse Laser-Induced Plasma method.

So, we have researched characteristics of several gas or different gas mixing rate at

atmospheric pressure. For example, SF6, CF3I, CO2, N2, O2, Ar, He and so on.

www.***.co.jp

Mechanism for Surface Charge Decay on Dielectrics

Dielectric materials are widely used for power equipment. Dielectric surface charge causes

“generating electro static discharge (ESD)”, “reducing performance of the insulation system”

and so on. In the worst case, ESD causes industrial hazards such as a fire or the explosion.

Recently, miniaturization is accelerating in the field of the electric devices, electric power

system, semiconductor and so on. This is because there are same merits. For example,

reducing the fuel consumption of car or airplane, reducing the number of mechanical parts,

and so on. However, if miniaturization is accelerating, we will confront some demerits.

Miniaturization applications have high electrical field and high temperature. These problem

lead to reduce performance of the insulation material.

So, we have researched the charge mechanism and decay process on several

dielectric materials under high electrical field.

www.***.co.jp

Analyzing for discharge and plasma temperature

To understand the plasma parameter is important for developments of efficient plasma

application and reliable insulation design.

Plasma-Chemical reaction is influenced

by the gas temperature and mean

electron energy.

Gas temperature in corona discharge

relates closely to defacement and

degradation of dielectric materials.

It’s important to make clarifying

statement about spark-over mechanism.

Plasma application field

Dielectric and electrical insulation field

So, we have investigated gas temperature of discharge or plasma.

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+ Systems & Software Engineering

Laboratory

+ Semiconductor analysis Laboratory

+ Audio Media Engineering Laboratory

+ Systems Architecture Laboratory

+ Network Design Laboratories

Department of Electronics Engineering

and Computer Science,

Faculty of Engineering

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Systems & Software Engineering Lab (1)

Prof. Tsuneo Nakanishi, email: [email protected]

Systems Engineering

Software Engineering

Product Line Engineering

Embedded Systems

Automotive Systems

Model Driven Development

Model Based Development

DevOps

Research Topics

www.***.co.jp

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Product line engineering is our specialty!

Domain Engineering Application Engineering

Management

Core Assets

Reuse

Construction

&

Maintenance

Defects Correction&

Enhancement

Product line engineering is a paradigm of software development to

construct multiple products by making disciplined reusing core assets.

We brought successful adoption of product line engineering with a joint

research with Japanese companies including Fujitsu Kyushu Network

Technologies and Aisin Seiki.


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Semiconductor analysis Lab (1)

Scanning Tunneling Microscope (STM) instruments

Metal-intercalated Graphene

Organic-Inorganic hybrid semiconductor systems

Supramolecular assembly on semiconducor substrate

Research Topics

Scanning Tunneling Microscope (STM)

instruments

Prof. Takayki Suzuki, email: [email protected]

www.***.co.jp

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Scanning Tunneling Microscope (STM) instrumentsThree Ultra-High Vacuum STM,

1. JSTM-4610 with Low-Energy Electron

Diffraction (LEED): For student training and

Graphene experiments

2. JSTM-4610 with LEED: For Graphene

experiments.

3. Low temperature Double-tip JSTM-4500XT

with Reflection High Energy Electron

Diffraction: For organic semiconductor

experiments.

1

2 3

Scanning Tunneling Microscope (STM) instruments

www.***.co.jp

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• Large area monolayer graphene used for future electronic devices.


Monolayer graphenesp2

MetalSiC

I. Gierz, et al., Phys. Rev. B 81 (2010) 235408.K.Yagyu, et al. Appl. Phys. Lett. 104 (2014) 053115.K.Yagyu, et al. Appl. Phys. Lett. 110 (2017) 131602.Y. Orimoto, et al. J. Phys. Chem. C 121 (2017) 7294.

STM image of Cu-intercalated graphene


www.***.co.jp

• Atomic structures and electronic properties aimed for

nanoelectronics.

Type 3

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DBC on Si(001)-𝟐 × 𝟏

T. Suzuki, et. al. Nano Letters 6 (2006) 138.T. Suzuki, et.al. J. Chem. Phys. 124 (2006) 054701.T. Suzuki, et. al. J. Chem. Phys. 124 (2006) 224708.T. Suzuki, et.al. Surf. Sci. 600 (2006) 5092.T. Suzuki, et. al. J. Chem. Phys. 142 (2015) 101904.P. Kocan, et. al. J. Phys. Chem. C 121 (2017) 3320.


www.***.co.jp

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TPA on Si(111)-

𝟑 × 𝟑-Ag

TCNQ on Si(111)-

𝟕 × 𝟑-In

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TPA on Si(111)-

𝜷 𝟑 × 𝟑-Bi

T. Suzuki, et. al. Phys. Chem. Chem. Phys. 11 (2009) 6498.T. Suzuki, et. al. Surf. Sci. 605 (2011) 1994.I.I. Rzeźnicka, et. al. Surf. Sci. 652 (2016) 46.

• Chemical and biological functionalization of semiconductor

surfaces.


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Research Topics Development of Spoken Dialog System Using AR and

Image Processing

Development of Hearing Support System for Elderly

Development of Honeybee Lifelog Monitoring System Using RFID Sensor and Image Processing

Development of Geo Database Application for Eruptive History Informatics

Development of Image Enhancement Algorithm for Deep Sea Environment

Key words: Spoken Language Processing, Acoustic Processing, Image Processing, Machine Learning, Artificial Intelligence

Audio Media Engineering Laboratory

Ass Prof Dr. Shinya Takahashi , Dr. Yujie Li E-mail: [email protected]

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Research Topics Computer systems.

Digital circuits,

Microarchitecture,

System architecture,

Operating systems

Current hot topic is approximate computing

Systems Architecture Laboratory

Prof. Toshinori Sato, Dr.Tomoaki Ukezono: [email protected]

Approximate Computing

• Approximate computing can trade

accuracy for power & performance.

• Many applications have ability of error

tolerance.

– Strictly accurate results are not required.

– Data mining, Deep Neural Networks

Can You Find Differences?

• If we cannot find any differences, it is better to

replace precise computing with approximate

one because the latter is more power efficient.

Image 1 (Precise) Image 2 (Approximate)

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Research Topics

Network control and design for content distribution

Spatially-Dispersed Caching in ICN

Cache control based on correlation among web objects

Cache control based on distance to originals in CDN

Information sharing using DTN at disasters

Control for cloud computing

Virtual machine trading among service providers

Economics of content distribution system

Optimal design of virtualized CDN

Analyzing impact of introducing CCN on profit of ISPs

Prof. Noriaki Kamiyama E-mail: [email protected]

Network Design Laboratories

www.***.co.jp

Content delivery: most popular service in Internet

Requested by name, whereas transferred by host address

Overhead resolving name before content delivery

Delivery platform: provided by CDN providers

independent of network providers

Difficult to optimize content location and server selection

Spatially-Dispersed Caching in ICN: ICN or CCN

Content serverUser terminal

Content

Router

Caches content at

routers on delivery routeDelivers content

from routers

ICN (Information-Centric Networking)

CCN (Content Centric Network)

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www.***.co.jpCache control based on correlation among web objects HTTP/2, SPDY

67% of users experienced a long waiting time every week when browsing webpages.

Amazon increased revenue 1% for every 0.1 second reduction in webpage load time.

HTTP/2 or SPDY

Reduces web response time by obtaining multiple web objects in parallel from identical cache server

To improve effect of HTTP/2, need to obtain many web objects from identical cache sever

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Cache

Server

User

Object

Small effect of HTTP/2 Large effect of HTTP/2

Cache

Server

Object

User

www.***.co.jp

Cache control based on distance to originals in CDNCache Replacement

When cache miss occurs, cache server obtains content from origin server, caches obtained content, and sends it to requesting user.

When available storage capacity is insufficient, some content items are removed from cache server using cache replacement algorithm.

Cache replacement algorithm determines effect of CDN.

Existing cache replacement algorithms

LRU (least recently used):

Removes content item which is least recently accessed

LFU (least frequently used):

Removes content item with smallest access frequency

Existing cache replacement algorithms only consider popularity of content.

www.***.co.jpOptimal design of virtualized CDN Virtualized CDN

Provides cache servers (CSs) using virtual machines (VMs)

Personalized CDN customized for each content provider (CP)

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Datacenter

CDN for CP 1 CDN for CP 2

Physical network

Virtual CS

Amazon CloudFront

CP can freely select virtual CS (VCS) among seven regions.

Selection of VCS regions affects cost of CP and user-perceived quality.

www.***.co.jpAnalyzing impact of introducing CCN on profit of ISPs Comparison of CDN and CCN

CDN: CDN provider deploys caches in regional ISPs.

CCN: Each ISP attaches caches at routers in its network.

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T-ISP: transit ISP, R-ISP: regional ISP, CP: content provider

user

T-ISP A

CPCDN

provider

R-ISP CR-ISP B

user

T-ISP A

CP

R-ISP C

ISP introducing CCN

cache

R-ISP B

CDN CCN

cache

CCN is introduced by each ISP based on

its business judgment.

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Notice

Students are required to understand English to discuss with

us.

Bachelor and master course students need to understand

Japanese if they require credit of lectures .

Doctor course students are required to understand minimum

Japanese to live in Japan.

Doctor course students must have a knowledge and method

to conduct their research.

Doctor course students shall have talent of abstraction.

Applicants of the post graduate students are requested to

solve a mathematical problems and submit research plan

written by themselves.

electric power laboratory department of electrical ......for example, sf 6, cf 3 i, co 2, n 2, o 2,...

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