Daijiro Komaki

Human activity recognition for a content search system considering situations of smartphone users

Smart-phone users can search for information about surrounding facilities or a route to their destination. However, it is difficult to get or search for information while walking because of low legibility. To address this problem, users have to stop walking or enlarge the screen. Our previously proposed system for smart-phone switches the information presentation policies in response to the users context. In this paper we describe our context recognition mechanism for this system. This mechanism estimates user context from sensors embedded in a smart-phone. We use a Support Vector Machine for the context classification and compare four types of feature values consisting of FFT and 3 types of Wavelet Transforms. Experimental results show that recognition rates are 87.2 % with FFT, 90.9 % with Gabor Wavelet, 91.8 % with Haar Wavelet, and 92.1 % with MexicanHat Wavelet.

Mobile search assistance from HCI aspect

Mobile internet access has become an important technology to our life. According to this trend, search engines have been providing search services for mobile phones. Since a mobile phone has a limited interface, such as a small screen and keypad, even simple interactions are burdensome for users. Therefore, to provide comfortable web browsing experience, efforts on HCI aspect are also essential. In this paper, we describe our studies that tackle this problem by HCI-based approach. We propose systems that reduce the number of operations on inputting a query to a search engine, enable clipping and saving a web content, and assist cooperative web search conducted by multiple mobile users.

A content search system considering the activity and context of a mobile user

People routinely carry mobile devices in their daily lives and obtain a variety of information from the Internet in many different situations. In searching for information (content) with a mobile device, a user’s activity (e.g., moving or stationary) and context (e.g., commuting in the morning or going downtown in the evening) often change, and such changes can affect the user’s degree of concentration on his or her mobile device’s display and information needs. Therefore, a search system should provide the user with an amount of information suitable for the current activity and a type of information suitable for the current context. In this study, we present the design and implementation of a content search system that considers a mobile user’s activity and context, with the goal of reducing the user’s operation load for content search. The proposed system switches between two kinds of content search systems according to the user’s activity: the location-based content search system is activated when the user is stationary (e.g., standing and sitting), while a menu-based content search system is activated when the user is moving (e.g., walking). Both systems present information according to user context. The location-based system presents detailed information via menus and a map according to location-based categories. The menu-based system presents only a few options to enable users to get content easily. Through user experiments, we confirmed that participants could get desired information more easily with this system than with a commercial search system.

Content comparison functions for mobile co-located collaborative web search

Due to the recent popularization of mobile devices, such as mobile phones and PDAs, most people have their own mobile devices in Japan. In this situation, a user can search the Web not only by himself, but together with his friends and families, which aims to find information that meets requirements from all of them. In such collaborative search, users first search the Web separately and collect contents of interest, and then, share the contents with others by showing a screen with each other. However, because mobile devices generally have a small screen, this process is burdensome for users. In this paper, to solve this problem, we propose an interface to support users engaged in collaborative search to share and compare their collected contents. The proposed interface provides functionalities to effectively share contents collected by all members and to add reviews in order to make content search and comparison easier.

A Menu-based Content Search Support System Considering Mobile User's Situations

Abstract Due to the popularization of mobile phones, many people search Web contents using their own mobile phones. Since people bring their mobile phones everywhere, they can search Web contents in various situations (e.g., walking and sitting). In particular, when users are walking, they cannot pay enough attentions to operate their devices and it is difficult to conduct complicated operations such as character inputting. In addition, users’ search objectives are also affected by the time and their location. To assist content search in such situations, in this paper, we propose a content search support system that presents a few options that enable mobile users to get desired contents easily considering the users’ situations. The system infers users’ situation based on sensory data and presents initial options considering users’ search objective corresponding to the inferred situation. Through a user experiment, we confirmed that participants could get desired information easily by using our system and it was effective to adaptively present options based on the inferred situations.

Design and implementation of a Click-Search interface for web browsing using cellular phones

It has become common to search for information on the web using cellular phones. However, since cellular phones only have numerical keys for inputting characters, users have to conduct laborious operations to input a keyword for a web search. In our previous work, we assumed information devices equipped with pointing devices and proposed a Click-Search method that enables users to perform a keyword search simply by pointing to and clicking on the desired word on a web page. This approach might be effective for web searches using cellular phones. However, since many cellular phones only have a direction pad as a pointing device, users still have to conduct laborious operations using the pad to move a pointer and point to a word. To solve this problem, we propose a Click-Search interface for cellular phone users that uses an expanding circle to select a word for a search. Using this interface, users can specify a keyword simply by pushing a few buttons.

A click-search interface for web browsing using cellular phones

Cellular phones are widely used to access the Web, and it has become common to search for information on the Web using cellular phones. However, since cellular phones only have numerical keys for inputting characters, users have to conduct laborious operations to input a keyword for Web search. In our previous work, we assumed information appliances equipped with pointing devices and proposed a Click-Search method that enables users to perform a keyword search simply by pointing and clicking the target word on a Web page. This approach might be effective for Web searches using cellular phones. However, since many cellular phones only have a, direction pad as a pointing device, users still have to conduct laborious operations using the pad to move a pointer and point to a word. To solve this problem, we propose a Click-Search interface for cellular phone users that uses an expanding circle to select a word for search. Using this interface, users can specify a keyword simply by pushing a few button.