List of Dissertation Abstract （Information Media and Environment Sciences Information Media Course）
Name

Tomoo OSHIKA

Yao XIAO

Title

Supervisor
Junji
SHIKATA

Katsunari
YOSHIOKA

High-functional encryption
from Identity based
homomorphic encryption

Abstract
Along with the development of network technology, emphasis is not only safety but also functionality.
Homomorphic encryption which allows computation on ciphertexts, generating an encrypted result,when decrypted, result of the operations had been performed on the plaintext. I studied whether
homomorphic can have various other functions at the same time.

A Study on Analysis of Social In recent years, targeted attacks that send malware-attached mails to the target have been increasing.
Engineering of Targeted

When the attached file is opened, it shows a decoy document that is relevant to the target in order to

Email Attack

conceal the infection. We collect decoy documents to infer the targeted individuals or organizations.
Recently the number of connected devices is increasing rapidly. While these IoT devices receive large

Zhiyong YANG

Katsunari
YOSHIOKA

Observation and Analysis of
Cyber Attacks in Home
Network

benefits from diverse services provided via Internet, there is a concern about cyber attacks against
them. Nevertheless, investigations and researches on cyber attacks in home networks are surprisingly
few and unexplored. In this study, we develop a home network testbed and test proof-of-concept
attacks that could potentially be conducted against these devices in home network and observe theireffect. Finally, we discuss the framework to evaluate home network security products.
By conducting the experiment presenting text with different contrast polarity conditions and getting its
subjective visibility, we found the visibility evaluation formula integrating contrast polarity of text.

Ryohei AKUTSU

Katsunori
OKAJIMA

Visibility evaluation formulaAlso, we analyzed the formula and revealed characteristics and limitation related to character size.

considering contrast polarity

Finally, experiment conducted for elderly people. Results suggested “contrast polarity effect” occurredof text and age of observer

by hazy media. Considering this effect and the age-related decline in contrast sensitivity, the visibility
evaluation formula for the elderly people was obtained, which can evaluate the visibility of bothcontrast polarity conditions.

A study on retrirval method
AkihiroTatsunoriof passage related to given

IIZUKAMORI

key-phrases in essay-type
examinan of world histry
Automatic Construction of

Kohei IIZUKATomoharu

Image Feature Quantity

NAGAO

Extractor Focused on
Analytical Property

In this research, the search unit in the automatic answer system of the University of Tokyo entrance
examination world history, the use of the query decomposed into the constituent words of the specified
phrase and the pseudo relevance using the search query extension by the feedback of the passage
acquired by the search. We proposed a feedback method. As a result of the evaluation experiment,
recall rate in search was improved by giving information on passages related to specified phrases.
In this paper, the authors propose an automatic construction method of image feature quantity extractor
with emphasis on analytical property. Proposed model is based on automatic construction of tree
structure image transformation (GMA) and feature quantity extractor (SIFTER). We conductcomparative experiments on the method and accuracy that restricted functions. Experimental results
show that the proposed system is effective.
In this paper, we construct a system that estimates the energy consumption of electric vehicle (EV)driving on roads without driving experience. To travel without worrying about running out a battery,

Kota ISOBE

An Estimation System of EV

EV users need to prepare a driving plan based on energy consumption in advance. To solve thisTakashiEnergy Consumption forproblem, we calculate to plan by finding the minimum/maximum power consumption from the

TOMII

Driving on Unexperienced

simulation when an EV travel the registered route. With this plan, once it is possible to know the limit

Roadsspot where we can reach and the place where there is a possibility of running out a battery. To evaluate
this system, we conducted driving EV experiments and verified the estimation accuracy of EV's energy
consumption.
Plant factories need to increase their harvest, but it takes many days in plant grows. In this paper, we

Yuki ITO

Tomoharu
NAGAO

Harvest Maximization at
Plant Factory using Bayesian
Optimization

propose improving method to limit sampling area in Bayesian optimization for such expensivefunctions. With the benchmark functions experiment, our method seemed to update the optimal
solution frequently, and finally found better solution than the original. In addition, we applied our
method to harvest maximization problem and could found the settings which we can grow lettuce
heavier in dry weight by 40% with than expert ones.

Construction of Energy LifeRyuhei

TakashiLog DB for Considering the

IBARAKITOMIIIntroduction Effect ofSmartgrid

In this research, we construct a consolidated database that accumulates energy life logs with unified
time granularity, and applies it to the simulation of energy balance in smart grid. In this paper, weanalyze the energy balance according to the introduction amount of the components of the smart gridby using real data, and showed that the integrated database is useful for examining the introduction
effect of smart grid.

Wataru UENO

Katsunari
YOSHIOKA

Tadahiro

Junji

UCHIKOSHISHIKATAA Study on Countermeasureof Malware that Evade
Security Analysis

Recently, in order to cope with increasing cyber-attacks, the defender makes use of analysis systemsuch as honeypot, a decoy system to monitor and analyze cyber attacks. However, it has been reported
that attackers detect analysis systems with various ways and evade their analysis. Therefore, in thispaper, we investigate, implement, and evaluate evasion-resilient cyber-attack analysis system.

A Study on Construction of

In this thesis, we construct cryptographic systems with advanced functionality based on the

Advanced Cryptographic

KEM/DEM framework. Specifically, we construct Forward Secure PKE and Anonymous Broadcast

Protocols Based on a

Encryption based on the KEM/DEM framework, and analyze requirements of KEM and DEM so that

Framework of Hybrid

the resulting systems are secure. As a result, we show that if the underlying KEM has an advanced

Encryptionfunctionality, then the resulting system can inherit its functionally.

Study on Efficient Threshold
Masahiro

Junji

Public-Key Encryption from a

EBINA

SHIKATA

Weak Complexity
Assumption.

A Public-key encryption is based on any complexity assumption. It is one of important research
directions to design from the weakest possible complexity assumption. In my thesis, we propose an
efficient threshold public-keyencryption system secure against chosen ciphertext attacks from the hardsearch problem. Furthermore, we show the construction for making some parameter length more
efficient and compare it with previous works.
In recent years, cryptographic techniques have been used for various information devices to protect the

A Study on Tamper Resistantinformation and communication contents therein. However, side-channel attacks using physical

Kenya

Tsutomu

Hardware for Advanced

information for information equipment pose a threat. The term "tamper resistance" which indicates

OKUTOMI

MATSUMOTO

Encryption Standard anddifficulty in deciphering information equipment is used. In order to improve the tamper resistance, we

Pairing Based Cryptography

will consider attack methods that can pose new threats to the currently used AES and pairing-based
cryptography expected to be used in the future.

A Study on Honeypot
Rina KATO

Katsunari
YOSHIOKA

Imitating a Remote

We built the honeypot imitating a remote monitoring and control system using the real data logger andMonitoring and Control

PLC, and observed accesses to the honeypot. As a result, we observed accessors who do not hesitate to

System Deployed incarry out highly aggressive operations, and those who seem to be aiming for investigation.

Infrastructure Facilities

When handling facial expressions in machine learning, it is necessary to give labels which are teacher
signals to facial expressions. However, from the viewpoint of cost of building a dataset, one-hot labels
Yoshihisa

Tomoharu

KANOU

NAGAO

Generation of Continuous
Facial Expression Space
without Emotional Labels

attached to emotions are given, and the continuity of facial expressions is often not considered. In thisresearch, we propose a method to generate face expression space by learning the continuity of facial
expressions separated from subject-specific features as latent spaces inside the model without usinglabels on facial expressions. In the experiment, visualization of latent space, image generation, andunsupervised facial expression classification task are conducted, and we verify the effectiveness of theseparated subject feature / facial expression feature and facial expression space
Convolutional neural networks (CNNs) show remarkable performance on image recognition tasks.

Dynamic Selection of Image
Yusei KAWAI

ShinichiProcessing Filters for

SHIRAKAWA

Convolutional Neural
Networks

Several studies report that the preprocessing by ordinary image processing filters helps to improve theperformance of CNNs. However, the selection of appropriate filters depending on datasets requires
trial-and-error or huge computational cost. This thesis proposes an efficient automatic selection
method of preprocessing filters by optimizing the probabilistic distribution for the filters during themodel training. The experiment using several datasets shows that the proposed method can contributeto improving predictive performance.
There are many studies on the cross-modal effects of the color of the beverage, but there is no study on

Daiki KOUNO

Katsunori
OKAJIMA

Effects of color and visualcloudiness on evaluation ofbeveragethe cross-modal effects on cloudiness of the beverage. Therefore, in this study, we conducted
experiments on the influence on the evaluation of the taste when changing the cloudiness as well as
color of the beverage with AR. As a result, it was possible to increase bitterness of green tea andfruitiness of fruit beverages due to visual cloudiness of the beverage, where as it was suggested whenthe visual cloudiness was too high. That the evaluation would be lowered.
Deep neural network (DNN) is a major machine learning model, which shows remarkable performance

Dynamic Structure
Shota SAITO

Shinichi
SHIRAKAWA

Optimization with
Regularization forControlling Model
Complexity of Deep Learningon various tasks, such as image recognition. Deploying to the limited computing resources, such as
smartphones, a memory efficient yet well-performed structure is required. This thesis focuses on amethod that simultaneously optimizes the weights and DNN structure by using the probabilistic modelof the structures and introduces a penalty term based on the model complexity into the objectivefunction to control the model complexity. From the experiment of connection selection in DNN for
image classification, the proposed method succeeded in reducing the number of weights by about 60%
while keeping the increase of the classification error rate within 1%.

Yusuke SAITO

Accuracy Evaluation to

We have run ECOLOG that estimates the energy consumption when driving in an EV with sensor data

Takashi

Estimate Energy

and stores it in the database as an EV Energy Life Log. In this paper, we verified the accuracy of the

TOMII

Consumption for EV Energy

EV energy consumption model in the ECOLOG. We applied cleansing to the data used for verification.

Life Log Database

As a result, the accuracy of the estimation model is improved.
Instrumentalists feel the difficulty when they play instruments such as the guitar, however it has not

Ro SAITO

Naoyoshi
TAMURA

Exercise-Song Proposal
System Research For
Supporting Guitar Practicebeen cleared that the difficulty depends on which elements of songs.

Our target is revealing therelationship between score and difficulty in terms of score statistics, over and above applying it toexercise-song proposal system.
In this research, we clarified 4 factor “fingering”, “frequency”, “rhythm”, and “speed” affect difficultyand enabled to calculate the difficulty from a score by analyzing evaluation scale of guitar players.
The security on sensors - "Instrumentation Security" is important for Cyber Physical System which

SatoruSAKURAZAWA

A Study of Instrumentation

takes information on physical space into cyber space and applies the processing result to physicalTsutomu

Security Evaluation System

space. In this paper, I show that I constructed a system to evaluate instrumentation security for ToF

MATSUMOTO

for ToF Depth-Image

depth-image cameras which are 3D distance sensors by executing the measurement pulse spoofing as

Camerasthe simulation attack. Furthermore, I show the evaluation results for the ToF depth-image cameras
which are on the market.
In this research, I focused on the tachistoscopic impression judgment. We presented various images

Temporal characteristics oftachistoscopically and evaluated "brightness" "beauty" and "preference". As a result, it showed that

TakuroKatsunori

impression judgment andbrightness perception and charm perception had mutual influence. We also suggested that feedback

SAWADA

OKAJIMAhierarchy of the brain

processing of charm perception may affect brightness perception. From the results of the experiment,

mechanism

we proposed hierarchy of the brain mechanism of impression judgment in which feedback andfeedforward processing of brightness and attraction perception are performed.

Seiya SUZUKI Tatsunori MORI

A study of a method forThis study proposes a method to extract cited texts in Web documents. And it aims to complete theExtraction of cited texts inentire extraction of source information in Web documents (in this study, source information means a

Web documents

pair of cited texts and source tests), with previous study.

With the spread of IoT devices and the evolution of computers, information traffic has dramatically

Ryota TANAKA

Junji
SHIKATAA Study on Encoding
Methods for Data Privacy andAuthenticator Compression

increased. There are research areas of encryption and authentication techniques based on coding
theory. In this thesis, for data privacy, we propose Wiretap Channel II with an active eavesdropper andderive upper and lower bounds of secrecy rates. In addition, for authenticator compression, we propose
construction of aggregate MACs with tracing based on bi-orthogonal justification data compression
codes.

A Study on Observation and
Kazuki

KatsunariCountermeasure of CyberTAMIYAYOSHIOKA

Attacks Using Real IoT
Devices

Cyber attacks against IoT devices are increasing in recent years. In this research, we conducted
research from two viewpoints of "observation" and "countermeasure" of cyber attacks on IoT devices.
In the research on "observation",I observed and analyzed the IP camera's peeping using decoy IP
camera. In the research on " countermeasures" , We proposed IoT malware removal and infection
prevention method and verified its effectiveness by using real devices.
Previous studies on facial expression recognition have not considered the facial direction and thestrength of the emotion. We conducted visual perceptual experiments as a function of facial direction

Moeka

Katsunori

NAKAJIMA

OKAJIMA

Effects of emotional strengthand found that the expression recognition performance decreases when the angle of the face deviates

and face direction in facialfrom the frontal position. In addition, we found that the accuracy of emotion recognition of side faces

emotion recognition

increases after visual perceptual learning. Finally, we conducted an experiment using stimuli morphedfrom neutral to each basic emotion. The results showed that observers felt the emotion strongly when
the facial landmarks are close to the basic emotion positions.
Notification of vulnerability and malware infection of IoT devices to the stakeholders is becoming

Shin NISHIDA

Katsunari
YOSHIOKA

A Study on Notification toincreasingly important. Therefore, various studies have been conducted to measure and compare theusers of IoT devices witheffectiveness of notifications in various setups. In this study, we focus on a case in which notification

security flaws

can be done via dedicated client software installed on users PCs and/or smart phones. We show adesign for notification experiment particularly for WarpDrive project.

In this paper, we model escapism, one of the elements of intrinsic motivation, and propose a method toimprove learning performance of agents' policy by applying the model to reinforcement learning. Our
ShimpeiTomoharu

NISHIMURA

NAGAO

Introduction of Escapism asmodel of escapism consists of the concept of stress and learning-task switching based on stress. To

Intrinsic Motivation to

examine effectiveness of the proposed model, we trained agents in the simulation environment. The

Reinforcement Learning

results showed that reinforcement learning with the proposed model outperformed naive reinforcement
learning. Furthermore, we also confirmed that our model was equivalent to previous model on intrinsic
motivation in terms of learning performance.
Stereo vision cameras are used in human life related systems or systems with a lot of financial damage
if it cannot run. Therefore, it can be said that raising instrumentation security of stereo cameras has

Hiroki NOHIRA

Tsutomu
MATSUMOTO

A Study on Instrumentationsocial significance. In this paper, we identify the instrumentation principle of the stereo vision camera

Security of Stereo Visionand the composition of its implementation, and show what kind of attack can be considered from the

Cameracomponents of each implementation. Then demonstrate that the attack is a threat. Furthermore, we willuse it in establishing the evaluation method of the instrumentation security of the stereo camera fromthe examination result of the attack method.
Presently, all the multivariate data can be accumulated due to the development of sensor / storage

A Visualization System ofdevice technologies and the publication of open data. However, it is generally difficult to analyze

Yuta

TakashiParallel Coordinate Plots

multivariate data, so support of a visualization system is indispensable. In this paper, we present a

HAMASAKITOMIIIntegrating Multivariate Datavisualization system of parallel coordinate plots extended by SPJ Query and operation snapshot. In

by SPJ Query

addition, we show availability of the proposed system by demonstration of Kosode Byobu and a car
traveling log.
Congestion alleviation and transfer time reduction of swarm transfer robots have been attracted

ChiakiTomoharu

HIRAYAMA

NAGAO

Alleviating Congestion of
Swarm Transfer Robots using
Classifier System

attention as the systems have been introduced to the real world, like logistic centers. To select paths
which can decrease congestion, we propose the dynamic Dijkstra’s algorithm that path-costs are
updated based on surrounding conditions of fixed points. We use Classifier Systems to get dynamic
path-cost update rules. Compared to a previous approach, the proposed method decreased by 2.9%
average transfer time and more than 7% max transfer time.

Utilization of historical

In recent years, question answering research for world history essay in university entrance exam

Yuta

Tatsunori

timeline by country in

become active. Previous research to solve this questions retrieve textbooks,but has a problem that the

FUKUHARA

MORI

question answering system toproposed method can't get required text in answer.Therefore, we propose using historical timeline bysolve world history essay

country and getting required text exhaustively.

TakuyaKatsunari

HOIZUMIYOSHIOKA

A study on discrimination ofuser environments using
network scan

In recent years, cyber attack targeting insecure IoT devices has become a great threat. It is believedthat one of the root causes is the lack of users' awareness on the device security. In this research, we
propose a method to grasp the security status of network devices owned by several hundreds ofvoluntary users of a security project by clustering the results of network scans on their devices.
In order to realize a quantum computer, post-quantum cryptography has attracted attention. In

Ryo MIYACHI

Tsutomu
MATSUMOTO

A Study on Tamper Resitant
Implementation for PostQuantum Cryptography

particular, Ring-LWE cryptosystems are more often implemented on embedded devices because of
their higher efficiency than other methods. There is a possibility that security of the system may be lost
due to vulnerability based on cryptographic implementation method when cryptography is operated bysmall and medium-sized nodes on the network In this research, side-channel security evaluation iscarried out with the aim of tamper resistant implementation for post-quantum cryptography.

The Improvement ofTakeshi

Tatsunori

MORIMOTO

MORI

Recognition Error of the Way
of Extracting Onomatopoeia
and Presumption of their
Impressions

Onomatopoeia is important in Japanese communication. Though identifying position of onomatopoeia
in sentences and presuming their impression is essential for workers engaged in onomatopoeia
research and Japanese language learner, the way of automating their processes isn't perfect. So we
propose the way of improving their problems.
A fuzzy extractor converts non-uniformly source into uniformly distributed output, and it is required to

Kenichi

Junji

YAMADA

SHIKATAA Study of Fuzzy Extractor
with Robustness and Small
Entropy Losshave small entropy loss which is the difference between the entropy of the source and the entropy ofthe output. A robust fuzzy extractor is a fuzzy extractor which can detect manipulation of the helper
strings. In this thesis, we propose a new robust fuzzy extractor under the assumption that we can know
a source distribution and show the entropy loss of our extractor is smaller than those of any previous
ones.

This thesis discusses scalar implicature and its defeasibility. Gazdar (1979) proposed a theory ofgeneration and cancellation of scalar implicatures, which was intended to predict when implicatures
are generated and when they get cancelled. Levinson (2000) discussed one example, which he argued
Shinichiro

Tomohiro

Defeasibility of scalar

the Gazdar theory cannot account for. The thesis reexamines Levinson’s argument and attempts to

YOSHIZAWA

FUZII

implicatures

show it is possible to modify Gazdar’s theory in a way that allows it to accommodate the example,
though Levinson himself didn’t discuss such a possibility. Then, it is observed that the modified
version of the Gazdar theory cannot be a real solution to the problem. The observation provides new
empirical support for Levinson’s original position.

A method using topic analysis
kazuya WAGA

Tatsunorifor estimating things in the

MORIbackground of short
document

Microblogging is a popular media for users to send information easily. Owing to its characteristics,
there are many short document .And sometimes it does not make it clear about things in the
background of document. In this research, we consider a method to estimate things behind short
document information. We propose a method doing a Web search by use of words contained in thesentences and narrowing down candidates of background things by topic analysis.
In this master’s thesis, I address the issues of positive and negative politeness in Japanese. I discusssuch works as Brown and Levinson (1987) and Matsumoto (1988), looking into applicability of Brown

Ekaterina

Tomohiro

EREMEEVA

FUJII

Aspects of positive andand Levinson’s theory to Japanese as well as Matsumoto’s objections to it. I attempt to dismantle

negative politeness in

Matsumoto’s analysis of relationship-acknowledgement devices (RAD) in Japanese. Further on, I

Japanese

perform an analysis of the two common Japanese politeness phenomena (sumimasen, analyzed as an
instance of negative politeness here, and sentence final particle ne, analyzed as an instance of positive
politeness here) that, in my view, support Brown and Levinson’s claims about universality of face.
Since humans use audition and wind sense when feeling the wind, the multi-modal phenomena always

The Influence of Audition on
Zhengnan XIA

KatsunoriWind Sense and the

OKAJIMA

Determination Mechanism ofWind Strength

occurs, but it is not known whether the cross-modal phenomenon occurs. In this study, we examined
the influence of audition on wind sense, and confirmed that the cross-modal phenomenon occurs whenfeeling the wind. Furthermore, we formulated the "feeling of wind strength" etc. Based on the resultsof this research, it is possible to control the "feeling of wind strength" by changing only the windsound, so it can be expected to be applied to movie theaters and VR systems where high realism isrequired.

To solve a drawing similarity retrieval problem, Text-Based Image Retrieval (TBIR), in which
keywords are previously attached to the images, is widely adopted. Using TBIR enables narrowing

Bingqing DU

Tomoharu
NAGAO

Similarity Computation for
Drawing Images Using Deep
Learning

down the retrieval result candidates, while Content-Based Image Retrieval (CBIR), which uses image
information instead of text information, is able to narrow even further.
This thesis argues image similarity retrieval methods for patent drawings. Considering the hugeamount of the image data provided by the patent drawings accumulated for decades, methods adopting
Deep Learning (DL) models are considered, and this thesis attempts to find out a DL model enabling
similarity compute between drawings in a variety of classes.
Recently the number of connected devices is increasing rapidly.

Jia XIONG

Katsunari

Experimental Analysis of

YOSHIOKA

Threats in the Home Network

With the advent of malware aiming

at these devices, many IoT devices are infected and become problematic．In this study, we do theexperimental analysis of threats in the home network and we discuss how to build malware sandboxes
using real IoT devices and investigate the adequacy of five devices for such purpose. We also present
the result of analyzing in-the-wild malware using the investigated devices.