Takako Hashimoto

Chiba University of Commerce · Commerce and Economics

The development of the COVID-19 vaccine and vaccination campaign was a significant concern for the people. In Japan, mass vaccination was initiated later than in other countries such as the United States, China, and Europe; however, vaccination coverage increased rapidly in this country, and in October 2021, Japan ranked 14th out of 229 countries i...

Background: Vaccines are promising tools to control the spread of COVID-19. An effective vaccination campaign requires government policies and community engagement, sharing experiences for social support, and voicing concerns about vaccine safety and efficiency. The increasing use of online social platforms allows us to trace large-scale communica...

Vaccines are promising tools to control the spread of COVID-19. An effective vaccination campaign requires government policies and community engagement, sharing experiences for social support, and voicing concerns to vaccine safety and efficiency. The increasing use of online social platforms allows us to trace large-scale communication and infer p...

In Japan, cashless is not yet popular but government and companies are devoted to the development of mobile payment methods. This research collected 241 Japanese users and applied decision trees algorithm. Six types of perceived risks (financial, privacy, performance, psychological, security, and time) were used and the categorized class is intenti...

During a disaster, social media can be both a source of help and of danger: Social media has a potential to diffuse rumors, and officials involved in disaster mitigation must react quickly to the spread of rumor on social media. In this paper, we investigate how topic diversity (i.e., homogeneity of opinions in a topic) depends on the truthfulness...

Much care should be given to the cases when there is a need to compare results of machine learning (ML) experiments performed with the usage of different Pseudo Random Number Generators (PRNGs). This is because the selection of PRNG can be regarded as a source of measurement error, e.g. in repeated N-fold Cross Validation (CV). It can be also impor...

The problem of feature selection has been an area of considerable research in machine learning. Feature selection is known to be particularly difficult in unsupervised learning because different subgroups of features can yield useful insights into the same dataset. In other words, many theoretically-right answers may exist for the same problem. Fur...

This paper explores the limitation of consistency-based measures in the context of feature selection. These kinds of filters are not very widespread in large-dimensionality problems. Typically, the number of selected of attributes is very small and the ability to do right predictions is a drawback. The principal contribution of this work is the int...

Feature selection is a useful tool for identifying which features, or attributes, of a dataset cause or explain the phenomena that the dataset describes, and improving the efficiency and accuracy of learning algorithms for discovering such phenomena. Consequently, feature selection has been studied intensively in machine learning research. However,...

This paper proposes a quality topic extraction on Twitter based on author’s role on bipartite networks. We suppose that author’s role which means who were in what group, affects the quality of extracted topics. Our proposed method expresses relations between authors and words as bipartite networks, explores author’s role by forming clusters using o...

It has been very significant to visualize time series big data. In the paper we shall discuss design on time series statistical data. As an example, we present an animation of Gibbs sampling process to clarify the time changes. Gibbs sampling is widely used MCMC algorithm in the deep learning field. We consider that an additional z-axis coordinate...

Social media offers a wealth of insight into how significant topics — such as the Great East Japan Earthquake, the Arab Spring, and the Boston Bombing — affect individuals. The scale of available data, however, can be intimidating: during the Great East Japan Earthquake, over 8 million tweets were sent each day from Japan alone. Conventional word v...

Social media offers a wealth of insight into how significant events? such as the Great East Japan Earthquake, and the Nepal Earthquake affect individuals. The scale of available data, however, can be intimidating: during the Great East Japan Earthquake, over 8 million tweets were sent each day from Japan alone. Conventional word vector-based event-...

In this paper, we will analyze monetary policy of the Bank of Japan, the central bank of Japan, just after the sales tax hike held in April 2014, through November 2014. The period matches the Japan’s turning point to the recession owing to the sales tax hike in April 2014. With the Abe second Cabinet which started in December 2012, the Bank set the...

In this paper, we will analyze monetary policy of the Bank of Japan, the central bank of Japan, under the second Abe Cabinet term which started in December 2012. The Bank set the "price stability target" at 2 percent in terms the year-on-year rate of change in the consumer price index in January 2013 and has made a commitment to achieving this targ...

After the sudden occurrence of East Japan Great Earthquake on 11 March 2011, triple disasters crippled the regular life of citizens of East Japan. A lot of people were affected, especially women victims suffered from different problems and worries: they had to care for elders, raise children, and find new jobs. Women also had specific needs of comm...

Presents the Women in Engineering Chair's goals for 2015.

A teleconference support system, establishing a teleconference among conference rooms, includes teleconference apparatuses, and a connection server including a conference venue information storage, a conference start judgment unit, and a teleconference apparatus connection unit. Each teleconference apparatus, disposed in each conference room, is pr...

After the East Japan Great Earthquake happened on Mar. 11, 2011, many affected people who lost houses, jobs and families fell into difficulties. Governmental agencies and NPOs supported them by offering relief supplies, foods, evacuation centers and temporary houses. When various supports were offered to affected people, if Governmental agencies an...

Social media is recognized as the important collaborations in today's information oriented society. Especially, after the global topics like a severe disaster (e.g. the East Japan Great Earthquake, Thailand floods etc.), people all over the world post their thoughts/opinions to social media and their behaviors are sometimes influenced by the discus...

We conducted topic extraction concerning the financial policy topics in Japan just after the East-Japan great earthquake disaster in 2011. The target document is text data of the Policy Board of the Bank of Japan financial policy meeting proceedings summaries. The topic extraction methods we used was the LDA algorithm. We extracted interesting thre...

We have been developing formula databases for our business math lectures. Our target is business mathematics and the main part is financial mathematics. To handle financial word problems, many statistical formulas and theorems must be referenced and used. We describe visualization of the statistical formula database in the paper. To teach statistic...

This paper proposes a time series topic extraction method to investigate the transitions of people's needs after the East Japan Great Earthquake using latent semantic analysis. Our target data is a blog about afflicted people's needs provided by a non-profit organization in Tohoku, Japan. The method crawls blog messages, extracts terms, and forms d...

After the East Japan Great Earthquake occurred in Japan on 11th March 2011, a large number of messages related to the earthquake were posted to social media web sites not only in Japan but also all over the world. Particularly, in Asian countries, a lot of topics concerned about the earthquake were observed. Exploring topics related to the earthqua...

This paper proposes a time series topic detection method to investigate changes in afflicted people's needs after the East Japan Great Earthquake using latent semantic analysis and singular vectors' pattern similarities. Our target data is a blog about afflicted people's needs provided by a non-profit organization in Tohoku, Japan. The method crawl...

After the East Japan Great Earthquake occurred in Japan on 11th March 2011, many messages related to the earthquake were posted to social media. Especially, in Asian countries, a lot of messages about the earthquake were posted, so that different topics such as concerning about damages by the earthquake, afflicted people were observed, etc. observe...

In many companies of the province of Tohoku (North-East Japan), stock prices were declining just after the East-Japan earthquake. However, on the other hand, some companies' stock prices rose in Tohoku. We have analyzed the reasons using text mining technologies on web data. In our studies, a combination of a stock price analysis and the text minin...

In solving word problems in mathematical economics, such as national income determination problems and various financial problems, two different knowledge bases are required: a database of math formulas and a database of economics theories. For this we have developed the knowledge bases, with which we offer our students an effective education suppo...

In this paper, we design a new method to explore the social context as a community mapping from a buzz marketing site. In this method, after extracting significant topical terms from messages in buzz marketing sites, first we construct a snapshot co-occurrence network at each time stamp. Next, we organize topic hierarchical structures from each co-...

Once a disaster occurs, people discuss various topics in social media such as electronic bulletin boards, SNSs and video sharing website, and their decision-making tends to be affected by discussions in social media. Under this circumstances, a mechanism to detect topics in social media has become important. This paper targets the East Japan Great...

With the recent advent of powerful mobile and smart technologies, the need for the development of navigation systems helping pedestrians is emerging. Unlike car users, pedestrians form a more heterogeneous group having different levels of physical abilities, personal preferences and needs. In this work a computational framework of multiple route ge...

Once a disaster occurs, people discuss various topics in social media such as electronic bulletin boards, SNSs and video services, and their decision-making tends to be affected by discussions in social media. Under the circumstance, a mechanism to detect topics in social media has become important. This paper targets the East Japan Great Earthquak...

The paper describes our web publication of visual teaching materials for business mathematics. The objective of the web site is to familiarize students with our visual approach for business mathematics at early stage. The significant advantage of visualization is that seeing the materials leads to better understanding of the mathematical process. E...

When the student is not able to solve a given problem, a plausible deductive reasoning process should be offered to him/her. Our final goal is a development of an e-Learning system which could help students not too much and not too little so that they can acquire as much deductive experience of independent work as possible. In the paper, we illustr...

The spread of video sharing services has made available an enormous number of videos. Even when searching video sharing services, too many videos are returned to view. Viewers want to classify videos to easily grasp results, because videos may include varied topics or differing viewpoints. Video clustering is one solution to addressing this problem...

Social media, which enable people to easily communicate and effectively share the information through the web, are rapidly spreading recently. In such media, effective topic extraction technique from messages has been significant so that trend topics and their reputation can be recognised. However, since messages contain redundancy and topic bounda...

Social media, in which individual users post their opinions and gradually build their consensus, is recognised as one of pervasive collaboration. Tracking topic transitions over time on a social media provides a rich insight into exploring its social context. This paper proposes a novel approach using a modularity measure which shows the quality of...

Social media had become worldwide phenomena. More than 80% of Internet's users are social media's users. When a disaster occurred, information needs will rise. Twitter is one of popular information resource especially in Indonesia. Because of that, twitter's information extraction system was needed. This research proposes a system that can detect t...

This paper proposes a method to detect unexpected correlation from between a current topic and products word of mouth in buzz marketing sites, which will be part of a new approach to marketing analysis. For example, in 2009, the super-flu virus spawned significant effects on various product marketing domains around the globe. In buzz marketing site...

When a disaster occurred, people try to acquire information through social media such as electronic bulletin boards, SNSs, and video services. Their decision-making tend to be affected by social media information. Sometimes, social media information is useful, so people can get valuable knowledge. On the other hand, social media information is occa...

Though route planning for navigation systems in the context of driving cars and other vehicles are becoming common with the introduction of GPS, current systems generally provide optimal routes as the shortest route based on travel time or travel distance. Route selection according to driver's subjective preference is still a topic of research. Wit...

This paper proposes a text mining method for detecting drastic changes of consumer behavior over time from buzz marketing sites, and applies it to finding the effects of the flu pandemic on consumer behavior in various marketing domains. It is expected that more air purifiers are sold due to the pandemic, and it is, actually, observed. By using our...

Video sharing services, which allow user to post videos and share them through the Web, are rapidly growing recently. There are some malicious posters who intentionally attach irrelevant metadata to the video with the aim of increasing the hit counts for promoting marketing advertisements or distributing pornography, etc. These inappropriate videos...

This paper presents a concept model for solving bond mathematics problems; it is the manner in which our knowledge concerning bond mathematics is organized into a cognitive architecture. We build a concept model for bond mathematics to achieve good organization and to integrate the knowledge for bond mathematics. The ultimate goal is to enable many...

A video-sharing service, where users can upload videos to, have rapidly spread recently. The number of videos in the service has increased dramatically as well as the number of users. With the rapid growth of the number of videos, we are faced with is having to arrange and categorize videos. However, it is difficult to let a computer aware the cont...

With the help of fast and cheap information technology GPS navigators for car navigation are becoming very common. But unlike vehicle users, pedestrians form a more heterogeneous group having different levels of physical abilities with varieties of conditions, personal preferences and needs. The lack of data to support pedestrian navigation also im...

Social computing services, which enable people to easily communicate and effectively share the information through the Web, are rapidly spreading recently. In such services, recognizing trend topics and analyzing their reputation from user messages have become significant. Effective topic extraction technique from messages in social computing servi...

Social computing services, which enable people to easily communicate and effectively share the information through the Web, have rapidly spread recently. In the marketing research domain, buzz marketing sites as social computing services have become important in recognizing the reputation of products hold with users. This paper proposes a reputatio...

Functional improvements to mobile terminals have made possible the spread of multimedia information delivery services. Especially for sports, a service that extracts important scenes and reports them to users has become popular. We take the approach that situational changes in a game's progress can be presented as state transitions, and devise an i...

Sports videos for mobile terminals and PCs and other multimedia information services have recently spread. The ability to efficiently extract significant scenes is important with these services. We proposed the personal digest making scheme (PDMS), which calculates the significance of events in a sports game based on video meta data and extracts si...

PDAs, cellular phones and other mobile terminals are now in common daily use. In Japan, high efficiency cellular phone service that can provide not only text and image data, but also video data has begun. We have developed, for these high efficiency cellular phones, a personal digest system that delivers professional baseball programs. The system...

A huge amount of multimedia content is available in the current Web environment. Streaming of video programs has become one of the popular Web-based information services. Automatic digest generation is an important application using video program streams. We have developed a digest making method called PDMS (Personal Digest Making Scheme). PDMS ext...

The growth of the Internet is placing severe demands on the existing telecommunications infrastructure. Especially, the growth of download accesses of movie-type contents has made Web traffic highly bursty, and this has become a significant problem for Internet users. In this paper, to solve the multimedia content download problem, we propose a new...

Content providers have recently started adding a variety of meta data to various video programs; these data provide primitive descriptors of the video contents. Personal digest viewing that uses the meta data is a new application in the digital broadcasting era. To build personal digests, semantic program structures must be constructed and signific...

This paper describes a TV program generation system using digest video scenes that are retrieved from video streams with the program indexes. The key features of the system are: (1) TV programs can be dynamically generated from digest video scenes selected by user preference. (2) Directions can be added using a happiness or sadness level based on t...

Recently, digital broadcasting has experienced rapid growth. Digital broadcasting can deliver additional data as program attachments, which viewers can use to flexibly browse and retrieve parts of the program on their TVreceiving terminals. They can also make personalized digests from the broadcast TV programs. This function is particularly useful...

This paper aims to present and verify the Extended Package-Segment Model. It provides a more flexible representation of logical structure of multimedia content than the Package-Segment Model (PS-Model) which we have already proposed. The PS-Model structure represents recursively ways to divide content. It is suitable to represent logical structure...