Content:1. SubjectCan faults due to deterioration over time or unexpectedfaults occurring in power equipment be detectedbeforehand ?2. Research ContentsHow to detect a symptom of faults ?(1) Radio Sensing, to locate the positions of deteriorationof insulating materials(2) Signal Processing, to locate abnormal positions inturbines, generators, and pumps3. Record of Joint Research(1) Chubu Electric Power Co. Inc. and Mitsubishi HeavyIndustries Ltd. for diagnosing turbine generators(2) Chubu Electric Power Co. Inc. and Hitachi Ltd. fordiagnosing pumps(3) Railway Technical Research Institute for diagnosingground coils of superconducting Maglev

Keywords Radio Sensing and Signal ProcessingE-mail: kawada@ee.tokushima-u.ac.jpTel. +81-88-656-7460Fax: +81-88-656-7460HP: http://pub2.db.tokushima-u.ac.jp/ERD/

person/25080/profile-ja.ht ml

Development of Insulation Diagnostic Techniques for Distribution Line Using FDTD Method Partial Discharge

Transformer

Antennas

0 20 40 60 80 100 120-1.5-1

-0.50

0.51

1.5

Time (ns)

E z (V/m

) Direction of Arrival Estimation

Electromagnetic Waves Emitted from a Partial Discharge Source, which is a Symptom of Deterioration of Insulating Materials.

Detection of Abnormal Vibration Using Wavelet Transform

Time-Frequency Visualization of Abnormal Vibration

Fig.1 Feedback control of a time delay system

Fig.2 Open loop system Fig.3 Closed loop system

Content:Systems with time delay belong to a class of infinite

dimensional systems. To construct a linear quadraticregulator of such a system, generally a solution of aninfinite dimensional Riccati equation is required tocalculate the feedback gain and a real-time integraloperation is included in the feedback law.To stabilize such systems, we propose a method toconstruct an inverse linear quadratic regulator. Thefeedback gain can be calculated from a solution of afinite dimensional Riccati equation or a finite dimensionallinear matrix inequality, and the feedback law is so-calledthe memoryless feedback which doesn’t include a real-time integral operation as shown in Fig. 1. The resultingclosed loop system can be shown to be stable (compareFig. 2 and Fig. 3 for example), and to be a linearquadratic regulator for some quadratic cost functional.Moreover, it is assured to have a good robustnessproperty against a class of static nonlinear perturbationsor dynamic linear perturbations in the input channel aswell as a linear quadratic regulator for systems withouttime delay.

Keywords time delay, LQ regulator, robust stabilityE-mail: kubo@ee.tokushima-u.ac.jpTel. +81-88-656-7466Fax: +81-88-656-7466

-80 -60 -40 -20 0 20 40 60 80-0.020-0.015-0.010-0.0050.0000.0050.0100.0150.020

20731

Curre

nt, A

Voltage, V

Sapphire substrate

P-layer N-layer

P-layer N-layer

P-metal N-metal Gold air bridge

1mm

1mm

300 350 400 450 500 550 600

40(20+20) type

--- 20mA--- 15mA--- 10mA--- 5mA--- 2mAIn

tensit

y, ar

b.un

its

Wavelength, nm

Keywords High Voltage AlGaInN

Content:Research of heuristic algorithmfor optimization problems in LSI layout design

For example,Obstacle avoiding rectilinear steiner tree (Fig.1)Voltage assignment in floorplan (Fig.2)

3D-IC floorplanning with TSV co-placement

Keywords Heuristic Algorithm, Optimization Problem, LSI Design

E-mail: simamoto@ee.tokushima-u.ac.jpTel. +81-88-656-7483Fax: +81-88-656-7471

Fig.1 Obstacle avoidingrectilinear steiner tree

Fig.2 Voltage assignment in floorplan

Fig.1 What is pulsed power Fig.2 Ns voltage pulse

Fig.4 Steamer discharges

Fig.3 Pulsed power application

Fig. 5 Water Treatment

Fig.6 Cancer therapy

Content: Pulse power is the technology of utilizing high power pulses obtained by compressing energy. We focus on green technologies and applications in bioengineering. Nanosecond pulsed power has been applied on environ-mental protection technology. It can efficiently produce streamer discharges as which were suitable for discharge-chemical processing. There are the high-efficient ozone production, the exhaust gas treatment of nitrogen oxide (NOx), and the water treatment for persistent substances. Applications in bioengineering utilize the influence of electric pulses and discharges on biological body. The influences can be controlled by the pulse width (spectrum), various applications can be expected. There are the production technology of micro algae biomass fuel and growth control of plants. We are developing the new cancer therapy and the control method of endoplasmic-reticulum-stress response aiming at prevention of disease, using nanosecond pulsed powers.

Keywords pulsed power, bioelectrics, pulse electric fieldE-mail: simon@tokushima-u.ac.jp>Tel. +81-88-656-7463Fax: +81-88-656-7463

100W X 1s

10GWX

10ns

Pow

er

TimeTime [ns]

Vo

lta

ge

[kV

]

150

100

50

0

-10 0 10 20

GasInlet

GasOutlet

Valve

Pump

Flow ofWater

Cu TapeGlass Pipe

Stainless Steel Wires

Content:The performance of communication network has been

drastically enhanced by adopting fiber-optictransmission technologies into the backbone networksand access networks. Recently, the demand forcommunication capacity is increasing even more,because of popularization of cloud type-application andtransportation of ultra-broadband contents such as high-definition moving pictures. The purpose of our laboratoryis bringing a significant progress of communicationnetwork by introduce novel functionality into the opticalcommunication network.

One of our topics of research is expanding opticaltransmission distance - capacity in backbone networks(Fig.1) by introducing phase-sensitive optical amplifiers(PSA) (Fig.2) as optical amplifier repeaters. PSAsamplify in-phase and de-amplify quadrature componentwith reference to phase-locked pump light in parametricamplifiers. Significant extension of optical transmissiondistance is expected by numerical simulation ontransmission system. We have also successfullydemonstrated the principles of PSA functionality.

Keywords optical communication,optical fiber, optical amplifieroptical signal processing

E-mail: takada@ee.tokushima-u.ac.jpTel. +81-88-656-7465

Optical Amplifiers(Repeaters)

WDM

Optical Transmitters

Optical Receivers

Optical transmission distance

Optical Parametric Medium

Pump Laser Optical PLL*

Photo Diode Optical Hybrid Input

Output

Fig. 2 Optical parametric phase sensitive amplifier (PSA)

(b) Basic configuration of PSA

(a) Fundamental operation of PSA

WDM

(*PLL : Phase lock loop)

/2

Fig.1 Configuration of backbone optical fiber transmission system

Content:Highly polarized UV emission devices were expected

to develop the applications, such as high resolutionimaging, high sensitive sensors, etc. The compactpolarization control device with high transmittance isrequired in order to develop integrated device for theseapplications.

One of the candidates to overcome the issue is thedevice using high contrast dielectric subwavelengthgrating (SWG) structure. In SWG, the pitch of the gratingis shorter than the wavelength of incident light. The Blochlike eigen-modes within SWG region resulting from thespatial periodicity of refractive index distribution interactswith incident light. As a result, the desirable opticalcharacteristics such as broadband high reflectivity andpolarization sensitivity are obtained with optimalstructures.We have investigated the polarization characteristics of

AlGaN-based UV-LED with SWG fabricated on the top ofLED surface, and demonstrated the feasibility of highpolarized UV-LED grown on c-plane sapphire.

Keywords photonic device, sub-wavelength grating, polarization control, nano deviceE-mail: naoi@ee.tokushima-u.ac.jpTel. +81-88-656-7447Fax: +81-88-656-7447

nbar

1

Fig.1 Sub-wavelength grating structure

(b) Periodic distribution of refractive index for light

(a) Schematic diagram

Fig.2 Electrical field distribution for TM light by FDTD theory

Fig.3 Fabricated sub-wavelength grating on UV-LED surface g g

Fig.4 Emission spectra from UV-LED

Fig.5 Polarization ratio from UV-LED with sub-wavelength grating

Graphene is very promising for future micro- and nano-electronic systems, because of its outstanding properties.Now, our main research interest is “graphene on SiC”.We can fabricate 10 mm-sq single-crystal mono-layergraphene using super-RTA (rapid thermal annealer). Thehigh-quality and uniform epitaxial graphene was grownon controlled step structures of 4H-SiC (0001) substrate.Graphene properties were evaluated using various kindsof nano-metrology tools. By using scanning probemicroscopy (SPM), contact conductance betweennanoprobe and graphene was measured. The contactresistance value was estimated to be the order of 10-9

cm2. The novel phenomena of graphene nanomembranewith bistable contact conductance states was observed.This electro-mechanical bistability of atomic layer switchcould represent a new path to nano-electro-mechanicalsystems. A final goal of our graphene research will benew functional devices for the post-Si era.

Keywords: graphene, SiC, nano-metrologyE-mail: nagase@ee.tokushima-u.ac.jpTel. +81-88-656-9716Fax: +81-88-656-9716HP : http://graphene.ee.tokushima-u.ac.jp/

Fig. 1: Logistic map, Fig. 2: One-parameterone of the most famous bifurcation diagram of theone-dimensional map Logistic map.generating chaos.

Fig. 3: Four autonomous Fig. 4: Four-phasechaotic circuits coupled quasi-synchronizationby one resistor. of chaos observed from the circuits in Fig. 3.

Content:1. Chaos Cryptosystems

Sensitive dependence of chaos on initial conditionsand parameters is exploited for various securityissues.

2. Chaos Communication SystemsContinuity of chaotic sequences generated from anidentical chaotic map is exploited to recover datacorrectly.

3. Complex NetworksVarious synchronization phenomena in coupledchaotic circuits are good models of various complexnetworks.

4. Nonlinear Time Series AnalysisChaos analysis is utilized to predict a trend ofnonlinear time series or to diagnose medical signals.

5. Data MiningSelf-organizing feature of artificial neural networks isexploited to carry out clustering of various data.

Keywords chaos, chaos cryptosystems,chaos communication systems, complexsystems, nonlinear time series analysis

E-mail: nishio@ee.tokushima-u.ac.jp>Tel. +81-88-656-7470Fax: +81-88-656-7471HP : http://nlab.ee.tokushima-u.ac.jp/nishio.htm

Content:BGA ICs have been often used for implementing

electronic circuits so as to satisfy shrinking requests inelectronic equipment. The ICs are soldered on a finepitched PCB. In the soldering process, open defects mayoccur. It is impossible to check the Interconnectsbetween the ICs and the PCB by visual inspection. Also,it is impossible to measure logic signals of theinterconnects with a probe. Thus, an IEEE 1149.1 testcircuit has been implemented inside ICs. However, opendefects may not be detected, even if the circuit isimplemented in an IC. Also, it is difficult to generate testinput vectors for detecting open defects and to locatedefective interconnects. Thus, we are developingelectrical interconnect test methods and DfT(design-for-testability) methods to detect open defects in theinterconnects.

Our developing test methods are based on supplycurrent that is made flow in our tests. Soft open defectsthat generate only additional small delay can be detectedand located besides hard open defects that generatelogical errors by our test methods. Keywords electrical interconnect test, open defect, boundary scan,

high reliable systemE-mail: tume@ee.tokushima-u.ac.jpTel. +81-88-656-7473Fax: +81-88-656-7473HP : http://tameone.ee.tokushima-u.ac.jp/~tume/

(a)Assembled printed circuit boards

(b)Open defect caused by electromigration

Fig.2 Electrical test with boundary scan test circuit

Fig.1 Targeted defects

Topics 1. Phasor measurements at demand sides and its applications

Developing an online monitoring of power system by multiple phasor measurement units with monitoring voltages at the outlets on the wall.

2. Management of distribution network with high penetration of photovoltaic generation units Investigating reasonable voltage regulation on high and low voltage distribution lines by cooperation of photovoltaic generation units and other apparatus.

3. Advanced power conversion to integrate multiple dc energy sources Integrating multiple dc voltage terminals to connect solar cells, batteries and loads easily, based on multilevel converter topology with flying capacitors.

4. Series-connected dc-dc converter for multi-end dc power transmission Developing a high frequency dc-dc power converter in series with a dc power transmission or distribution line to provide multi -ends.

5. Power modulations of distributed energy resources for frequency control Developing a voltage phasor modulation of grid-connected converters to regulate the system frequency as much as possible.

Keywords: Smart Grid, Reliability, Stability, Power Quality Field: Power system and power electronics E-mail: hojo @ ee.tokushima-u.ac.jp Tel/Fax. 088-656-7452

Fig. 1 My major researches.

Fig. 2 Grid monitoring. Fig. 3 Dc sources integration.

Content:In recent years, various systems coexisted within

human such as industrial machines and life supportsystems tend to increase. In addition, a highperformance and a high accuracy for these systems arestrongly required. To meet these requirements, we makeapplied researches on a control system using anintelligent information processing technique on the basisof biologically inspired approaches. For example, wepropose the design and implementation methods of thecontrol system combining soft-computing techniques(fuzzy, neural network, etc.) and control theories. Currentresearch themes are listed below:

Output prediction of wind or photovoltaic powergenerator using weather forecast modelCooperative control of multiple mobile robot systemAdaptive gait control for quadruped robot using centralpattern generator networkOperator’s support system for remote controlled robot

Keywords intelligent control, robot, wind energy and photovoltaic power generation, rehabilitation system

E-mail: yasuno.takashi@tokushima-u.ac.jpTel. +81-88-656-7458Fax: +81-88-656-7458HP : http://www-sky.ee.tokushima-u.ac.jp

Remote control robotRenewable energy system

Multi-legged robot Power assist knee orthosis

Multiple mobile robots Self-driving car

Content:With the miniaturization of silicon transistors in the end of

20th century, there was rapid development in the computerinformation systems. The guiding principle is the scaling rule.With the decreasing of the device dimensions, high speed,low power consumption, high density integration, low price arespontaneously realized. To expand the potentials of themicroelectronics to the application on communication,consumer electrical appliances, lighting and power electronics,it is necessary to achieve high voltage and high power. Tomaintain the high voltage and miniaturization compatibly,silicon technology is limited. It is necessary to introduce widebandgap semiconductors. A prospective candidate is galliumnitride (GaN). GaN blue light emitting diodes have alreadybecome commercialized. It is also being developed to realizegeneral lighting as a white source. In this laboratory, using thesame material of GaN, transistors, diodes, chemical sensorsand integrated circuits are being developed for theapplications in microwave communication and powerelectronics. Recently, in detail, we are focusing on GaNSchottky diode for microwave rectification (Fig. 1), high-frequency AlGaN/GaN HFET using electron-beam lithography(Fig. 2, 3), E-mode GaN MOSFET for power electronics andchemical sensor on AlGaN/GaN heterostructure

Keywords wide bandgap semiconductor,electron devices, sensors, monolithicallyintegrated circuits.E-mail: jpao@ee.tokushima-u.ac.jpTel. +81-88-656-7442Fax: +81-88-656-7442HP : http://wwww.ao-lab.net

Since the electrical characteristics of graphene field-effect transistors (FETs) are very sensitive for theirenvironmental condition, the graphene FETs have highpotential for chemical and biological sensors. In ourlaboratory, various sensors based on graphene FETs areinvestigated. The graphene FETs can be operated in thebuffer solution by top-gated operation from a referenceelectrode without any passivation film owing to their largepotential window. And their transconductance was morethan 200 times larger than that of the conventional back-gated operation in vacuum. The drain current increasedwith increasing the solution pH. And the graphene FETsdetected the charges in proteins. To detect the specificprotein, aptamers were functionalized on the graphenesurface. As a result, Aptamer-modified graphene FETsdetected the target molecule, and their sensitivity wascomparable for other aptamer-based biosensors.

Keywords graphene, device, biosensorE-mail: ohno@ee.tokushima-u.ac.jpTel. +81-88-656-7439Fax: +81-88-656-7439HP : http://graphene.ee.tokushima-u.ac.jp/

0 10 20 30 40 50 6034.8

35.2

35.6

36.0

36.4

IgESA

Drai

n cu

rrent

(μA)

Time (min)

BSA

-0.10 -0.05 0.00 0.05 0.10

0.15

0.18

0.21

0.24

7.85.84.8

Cond

ucta

nce

(mS)

Top-gate voltage (V vs Ag/AgCl)

pH 4.0

Graphene device fabrication

5 μm

Graphene FET Graphene-FET based biosensors

0 20 40 60 80 100

8

10

128.2

7.87.2

6.6

5.8

5.14.94.84.6Drai

n cu

rrent

(μA)

Time (min)

4.04.3pH

Detection of solution pH

Sensing results

Receptor functionalization and specific protein detection

With the widely spread of video applications, novel codingalgorithms which can answer many kinds of emergingdemands are highly required. Our research group is devotingto propose good ideas concerning the following themes.1. Improvements of the algorithms of HEVC and its low

complexity and low power VLSI architecture for the nextgeneration applications which are over 4K resolutions. Thealgorithms and architectures are concerning the intracoding, motion estimation, and deblocking filter.

2. Scalable video coding algorithms which are suitable forhigh resolution applications. We will make full use of thehigh correlations between base layer and enhancementlayer to propose new algorithms to improve the codingefficiency.

3. Highly parallel processing video coding algorithms onmany core platforms. Most of traditional coding algorithmsutilize the coding parameters of adjacent blocks toimprove coding efficiency. However, this coding structurehas essential demerit for parallel processing. As shown inFig.2, our motivation is to find new coding structure whichcan achieve higher parallel coding performance.

Keywords H.265/HEVC, Scalable Video coding(SVC),Parallel Video Coding

Content:Discharge plasma reactors consisting of a massive high

voltage generator and discharge electrodes are more likely tobecome large-scale system. We have proposed and studiedvarious types of compact plasma reactors using piezoelectricdevices. Piezoelectric transformers (PTs) that act as compacthigh-voltage generator have been widely embedded in abacklight invertor for LCDs. Our proposed plasma reactorsfeature compact configurations because the devices serve asboth high-voltage source and discharge electrode. Non-thermal plasmas, such as corona discharge, glow dischargeand dielectric barrier discharge (Fig. 1(a)(b)) can be producedusing the plasma reactors. Several applications of the plasmareactors to ozone generators (Fig. 1(c)) and vacuumultraviolet light source have been demonstrated. We have also promoted actively other research in

generation, diagnosis and applications of non-thermalatmospheric pressure plasma, including in-situ measurementof ozone density inside DBD ozone generator (Fig. 2) andsurrounding gas-fed (SGF) plasma jet (Fig. 3).

Keywords Dielectric barrier discharge, ozone, plasma jet

E-mail: teranishi@ee.tokushima-u.ac.jpTel. +81-88-656-7454Fax: +81-88-656-7454http://pub2.db.tokushima-u.ac.jp/ERD/person/155803/profile-ja.html

Fig. 1 Compact plasma reactor using piezoelectric device and its application

(a) Configuration

(b) Discharge plasma

(c) Application to ozone generator

ofsu

KK

TTeFFhhtu.

KK

EETT

(a) He/Air

(b) He/O2

Fig. 3 SGF Plasma jet

application

FFigFig. 2 In-situ O3 measurement by laser optical absorption

Ozonizer DPSS laser

Photo detector

Keywords femtosecond laser, ablationE-mail: tomita@tokushima-u.ac.jpTel. +81-88-656-7445Fax: +81-88-656-7445HP : http://pub2.db.tokushima-u.ac.jp/

ERD/person/ 82121/profile-en.htmlFig.2 : Electrical conduction control by fs laser modification

The material modification due to the femtosecond laserirradiation on wide bandgap semiconductors has been studied.The spontaneous formation of nano-periodic structures andthe amorphization due rapid heating and cooling processoccurs after femtosecond laser irradiation. Wide bandgapsemiconductors can be processed through the multi-photonprocess because of their transparency to femtosecond laserbeam.

Fig. 1 shows Raman spectra after the femtosecond laserirradiation on the interface between silicon carbide and nickel.D and G bands due to carbon was observed, and thisindicates that the carbon atom reached the nickel surface.

Fig. 2 shows the schematic of electrical conduction controlby fs laser modification. The femtosecond laser beam isirradiated between two metal contacts on semiconductor. Withincreasing the irradiation fluence, the local electricalconductivity abruptly decreased at the threshold fluence.

Fig.1 : Raman spectra with femtosecond laser irradiation on the interface between nickel and silicon carbide

Content:Nitride semiconductors are one of the most attractive

candidates for LEDs. The problem of the crystal growthof nitrides is no suitable substrate with good latticematching and low price.In order to obtain nitride substrates at low cost, we grow

GaN by a direct synthesis method (DSM) and AlN by asublimation method (or physical vapor transport). Bothmethods are low-cost growth method.Figure 1(a) shows the surface and cross sectional

images of the c-face GaN grown on c-plane sapphire and(b) a-face GaN on r-plane sapphire. Both grown layersare relatively high quality and can be used as substratesfor the growth of nitrides.Figure 1(c) shows the AlN layer grown by a sublimation

method. The grown layer is relatively high quality. Wegrew AlGaN by MOCVD on the AlN substrate and thegrown AlGaN layer shows good luminescence.

Keywords AlN, GaN, bulk crystal growthE-mail: nishino@ee.tokushima-u.ac.jpTel. +81-88-656-7464Fax: +81-88-656-7464

Cross sectionSurface

(a)

(b)

(c)

Fig.1: Surface and cross sectional images of the grown layers.

c-face GaN

a-face GaN

c-face AlN

Content:In recent highly integrated VLSIs, cost of testing is a

major problem. To alleviate the difficulty in testing, designfor testability techniques are widely used. In our researchlab, we develop methods for reducing test cost such astest data volume, test application time, area overhead oftest circuit, and for improving test quality especially indelay testing. One of the techniques is design fortestability method for small delay faults using time-to-digital converter embedded in boundary scan calledTDCBS, shown in the figures. The boundary scan cellsare modified to be able to form a time-to-digital converterthat is utilized for detecting delay. Using this architecture,defects like opens and shorts can be detected as extradelay caused by such defects even if the delay is smalland cannot be detected by conventional logic test. Thefeasibility of the proposed methods is estimated by bothsimulation and experiments of fabricated chips.

Keywords design for testability, VLSI testing, delay faults, test cost reductionE-mail: h.yotsuyanagi@tokushima-u.ac.jpTel. +81-88-656-9183Fax: +81-88-656-9183

Fig.1 overview of design for testability

Fig.3 layout of an experimental chip

Fig.2 Boundary scan with TDC

Content:According to the vital statistics from Ministry of Health,

Labour and Welfare, 33% of Japanese are died bydiseases related to the circulatory system. It is well-known that diet modification and an appropriate exerciseare effective to prevent these diseases. If we have aportable device which can evaluate the circulatorysystem and exercise habit, it is expected to suppressthese diseases and medical care costs.We have developed a portable measurement device(Fig. 1) for blood flow velocity (BFV) and investigated therelationship to various conditions for hundreds ofsubjects. As results of them, BFV waveforms showremarkable trends corresponding to aging and exercisehabit as shown in Fig. 2. These trends may reflect extentof atherosclerosis. We confirmed that they are caused bycompliance of the arteries by use of the multi-branchedarterial segment as shown in Fig.3.

Keywords Ultrasound doppler, atherosclerosis, bloodflow velocityE-mail: makutaga@ee.tokushima-u.ac.jpTel. +81-88-656-7477Fax: +81-88-656-7477

Fig 1. Prototype of a measurement device for blood flow velocity(BFV) and typical waveform of BFV in the carotid artery

Fig 2. Change of BFV waveforms with age and exercise

Fig 3. Change of BFV waveforms for different compliance of the arteries (computer simulation)

Content:Coupled oscillatory systems are good models to express

essential role of high-dimensional nonlinear phenomenaoccurring in the of natural sciences. Recently, manystudies have been investigated synchronization ofchaotic circuits. It is applied in the of engineering,physics and biology and so on.In this study, we apply coupled oscillatory systems to

modeling of social network using chaotic circuit (Fig. 1, 2).The chaotic circuits are placed on 2-dimensional spaceand are coupled with the distance information. By usingcomputer simulations and circuit experiments, we obtainclustering result as shown in Fig. 3. Figure 4 shows thesynchronization phenomena between the groups.Furthermore, we confirm that the number of clusteringchanges when the coupling strength is changed (Fig. 5).In our future works, we would like to apply the proposed

system for more complex social network by usingdifferent frequency of oscillators.

Keywords coupled oscillators, synchronization, clusteringE-mail:

C

L1 L2

-r

i1 i2

vvd

Fig. 1 Chaotic circuit

Group 1

Group 2

Group 3

Group 4

41020.0 41040.0 41060.0 41080.0 41000.1 41020.1 41040.1

Fig. 2 Chaotic attractor

Fig. 3 Clustering result Fig. 4 Synchronization

Fig. 5 Clustering phenomena with coupling strength

Content:There are a lot of patients who suffer from chronic disease(e.g. obstructive sleep apnea and a bowel disease etc.).Recently the prevalence of these diseases is likely to beincreasing in many countries. Polysomnography (PSG) andendoscopic test have been used for the diagnosis. Howeverthese tests are inconvenience and expensive. Our researchgroup hypothesizes that the information on these diseasesshould be embedded in biological sounds (e.g. snoring andbowel sounds) obtained from the patients. Biological soundscan be simply acquired via non-contact and/or non-invasivemeasurements. The target of our study is to develop theautomated diagnosis system based on the analysis ofbiological sounds. We are currently in the process ofdeveloping new sophisticated techniques for future medicalapplications. Biological sound-based techniques can beexpected to provide an attractive alternative to theconventional test for chronic disease.

Keywords Biomedical signal processing and bio-medicalinstrumentationE-mail: emoto@ee.tokushima-u.ac.jpTel. +81-88-656-7476

Fig.1 A sample of snoring sound recordings

Fig.2 A sample of bowel sound recordings

Content:Coherent optical communication technologies have

been studied to improve transmission capacity of opticalfiber transmission systems that consist of backbonenetworks and access networks. However, each networkhas major issues concerning introduction of the coherenttechnologies.[Backbone networks] The transmission distance islimited by additive noise from linear amplifiers; therefore,the transmitted optical signals frequently need to beregenerate to avoid such noise by repeaters that arerelatively expensive.[Access networks] Cost and power dissipation of theconventional coherent receiver are not acceptable forconsumer use.To solve the above problems, we are studying aboutphase-sensitive optical amplifier repeaters as depicted inFig. 1. and the access networks based on multi-levelmodulated signals interleaved with reference light asshown in Fig. 2.

Keywords Coherent optical communications, Phase-sensitive optical amplifier, Multi-level modulated signalsinterleaved with reference light

E-mail: okamura@ee.tokushima-u.ac.jpTel.Fig.2. Optical access NWs

based on interleaved scheme.

Fig.1. Backbone NWs with PSAs

< > Content:Photocatalyst has been attracting much attention as a

material for environmental conservation and new energyproduction. The advantage is that the photocatalytic activity isactivated semipermanently while the surface is irradiated withlight. TiO2 is a leading candidate as the photocatalyst. Thisreason is that the photocatalytic activity is activated easilyunder irradiation with near UV-visible light and that TiO2 ishardly dissolved by its own photocatalytic activity. Since TiO2is an inorganic compound, TiO2 is harmless for human andearth, and is stable in aqueous media and reactive gas. Thethin films, rather than the powders, are required from theviewpoint of the practical application such as large areacoating. The photocatalytic activity induced by use of the thinfilms, however, is less enhanced than that induced by use ofthe powders.

We have been studying TiO2 thin films with excellentphotocatalytic activity by using a magnetron facing targetsputtering deposition device developed by our group. Thecharacteristic of the deposition device is that the anatase thinfilms is fabricated without heating the substrate andperforming the post-annealing. We have also been studyingthe anatase films treated by using an atmospheric pressureplasma device developed by our group, in order to furtherenhance the original photocatalytic activity. The characteristicof the treatment device is that the surface treatment isperformed easily in the absence of expensive vacuum pumps.

Keywords Photocatalyst, Wide band-gap semiconductor,Plasma electronicsE-mail: retsuo@ee.tokushima-u.ac.jpTel. +81-88-656-7441Fax: +81-88-656-7441

Environmental conservation

New energy production

light

humanearth

Semiconductor Plasma Electronics

PVD sputtering DBD plasmas

TiO2 thin film

Photocatalytic Thin Film

20 30 40 50

X-r

ay in

tens

ity (A

rb. u

nit)

2 (deg.)

Anatase (101)

Content:The swarm robotics has a problem on the control

system design cause of voluminous measuredinformation and motion patterns. Therefore, we proposethe control system which uses soft computing schemee.g. neural networks (NN), fuzzy system and geneticalgorithm (GA).

The left figures are our proposed cooperative controlsystem for swarm robots using complex-valued NN(CVNN) and GA. The CVNN can treat a two dimensionalposition information and adaptable for control of mobilerobots. The system inputs a position information forCVNN and outputs a velocity vector and parameters ofCVNN are optimized by GA. We confirmed a trackingperformance for desired conveyance orbit, and a faulttolerance performances of some robot’s breakdown.

Moreover, we propose an extraction system of humanoperation skills using datamining method and analyze abehavior of robots basis on simple motion rules.

Keywords Swarm robotics, Machine learning, Cooperative control

E-mail: suzuki.hiroshi@tokushima-u.ac.jpTel. +81-88-656-7455Fax: +81-88-656-7455HP : http://www-sky.ee.tokushima-u.ac.jp/

11

Input Layer Output Layer

1

DesiredOutput

Hidden Layer

12

x yiTG TG

[ ] [ ]k kx yiR T R T

[ ] *[ ] [ ] *[ ]k k k kx yiR R R R

[ ] [ ]k kx yiV V

Complex-valued NNSwarm robots

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xis [

cm]

t = 0.0 s

t = 31.0 s

t = 63.0 s

MobileRobots

ConveyanceTarget

Desired conveyance orbit

Trajectory of conveyance target

Y A

xis [

cm]

maxer

Experimental Result

Fault tolerance

Content: An electric motor is used in ordinary homes, industrial field, and so on, and an AC motor is especially used from the view of the controllability, efficiency, and miniaturization. However, we need to attach a position sensor to the motor in order to control the motor. This causes the problem which is an increase in costs, increasing in size, and complication of the control device. There is a difference between industrial field motor and ordinary homes motor for method of controlling. Since the industrial field motor requires to control highly, it makes use of an expensive and high precise position sensor which is shown in Fig 1(a) . The ordinary homes motor is driven by using a cheap position sensor. Nevertheless, it causes a sacrifice of controlling. Thus, we are trying to develop controlling system which is able to give the motor high performance using the cheap sensor. It is possible to drive the motor if we add logic circuit and controlling program in order to achieve the object. It can be similar to the controlling system using a high precise position sensor. In addition, we are using a brushless DC motor as an AC motor, and we can keep the driving method which suppresses the switching loss. We also expect the improvement of efficiency.

Keywords： Brushless DC motor ,

High speed response

E-mail: yamaken@ee.tokushima-u.ac.jp

Tel. +81-88-656-7451

Fax: +81-88-656-7451

コンタクト不良

Position sensor(Hall IC)

(a) An industrial field AC motor(AC servomotor)

Position sensor(Encoder)

(b) An ordinary homes AC motor(Brushless DC Motor)

Fig1 The example of our laboratory’s AC motor

Fig2 The example of our laboratory’s

developing controlling circuit device