Research

We have summarized the requirements and functions of pro-beam road lighting to design specific light distribution of Pro-beam lighting to increase the visibility of pedestrians crossing the road through optical simulation and visibility evaluation experiments. Using the prototype light fixture, we have evaluated drivers’ visibility of pedestrians who are standing still and measured the time until drivers detect pedestrians at intersections using video images. As a result, we have confirmed that the Pro-beam lighting system provides higher visibility of the entire road space, including the oncoming lane, and helps drivers quickly detect pedestrians crossing the road not only from the right but also from the left. We are now working on the design and development of a light fixture for practical use as a road light by developing the prototype light fixture.

Research

According to a survey by the Tokyo Fire Department in 2014, approximately 80% of all cases of emergency transportation of elderly people are due to accidents involving falls. Since their consciousness cannot keep up with their declining physical abilities, they stumble over small steps, footwear, or clothing. Much research is done on the detection of falls, but it is too late after the actual fall. Therefore, we decided to eliminate the causes of falls by detecting the areas where people often stumble. Wearable devices have problems with forgetfulness and psychological resistance to wearing it, while non-wearable devices such as surveillance cameras have problems with blind spots and privacy protection. In this study, an acceleration sensor is attached to normal sandals to detect a stumble, while a network of infrared sensors installed on the ceiling works in conjunction to identify the location of the stumble. In our experiments, we were able to distinguish falls easily, but the accuracy rate of distinguishing stumbling from normal walking is currently only about 1/4, so we hope to improve the accuracy in the future.

Research

We have succeeded in establishing associations and similarities between different media, and developed an associative search scheme that takes ambiguity of multimedia information into consideration (fused search). We have also realized a new search engine and interface by quickly introducing modeling of personal preferences through user networks and visualization of similarities in preferences through user interfaces (personal adaptive search). Use of the search engine and interface enables a completely new search that effectively utilizes the polysemy and ambiguity inherent in multimedia contents.

Research

Through this research, we are conducting an international joint research project on content tourism (the act of actually visiting a place that is given meaning by a “story” or “work” and its constituent elements, and experiencing the relevant content) with the following three objectives:
First, we will clarify the role that such tourism plays in understanding others by rethinking content tourism from the perspective of the propagation and receipt of pop culture. Secondly, based on this, we will consider how to create a model exchange-oriented tourism town with content at its core. Thirdly, we will focus on the East Asian region, where Japan's geopolitical situation calls for international mutual understanding, and consider the possibilities and challenges that content tourism, triggered by Japanese content, has for Japan's cultural security.

Research

We are conducting research to apply "interviews" to policies and activities. Local residents, researchers, and students collaborate to investigate people, nature, history, culture, and social issues in local communities, to identify issues, think of solutions, and consider the future of the region. We are practicing and applying the methods of interviewing and verbatim recording as tools for this purpose. We are researching the possibilities of qualitative research (interviews and verbatim recording) as a way of visualizing what cannot be seen in conventional quantitative research (statistics and questionnaires) and workshops, and to build relationships of trust.

Research

This is the first attempt in Japan to implement a consolidated compact city project. In Yubari, we are promoting reorganization into an urban area of an appropriate size through downsizing, while creating a system of relocation and settlement to form local communities, and reduce the maintenance and management costs of urban infrastructure facilities. In the course of creating a compact city, we promote consolidation of the urban area for the first 10 years while maintaining local communities, and then consolidate local communities into a central urban hub over the next 10 years. This allows residents to continue living in Yubari at ease, even while the consolidation process is under way. In cooperation with Yubari City, we have already completed the relocation and consolidation of residents in the Mayachi district of Yubari.
Our efforts have been published in research papers and the mass media, and we have received many inquiries from cities facing similar issues.

Research

The purpose of this study is to elucidate the process of cooperation and value creation in a community-type workspace. A community-type workspace is an open workspace where individuals share information and knowledge with other through communication, and create value through collaboration according to the situation. A coworking space is a typical example of such a place, and in recent years, it has been becoming more and more popular in Europe, the U.S., and the rest of the world. In the background, there is a movement of questioning the highly uniform interaction and cooperation among members in closed spaces, a system that is still dominant in organizations and local communities, and to achieve both individual autonomy and solidarity. This research is expected to provide knowledge that will contribute to the design and operation of such workspaces, as well as their organizational and social utilization, which are still largely unknown.

Research

At this laboratory we are using GIS to study the use of geospatial information, such as Geospatial Information Authority (GSI) maps and digital national land information, maintained by the national government as well as open data maintained by local governments and big data such as movement history acquired by GPS. For example, the results of this research are being used to support the formulation of plans for tsunami evacuation in snowy and cold regions. The winter environment in snowy and cold regions (frozen road surfaces, reduced road width due to snow, etc.) makes tsunami evacuation in coastal areas extremely difficult. At our laboratory we generate a lot of information necessary for planning, such as the demarcation of difficult-to-evacuate areas, the estimation of difficult-to-evacuate populations, and evaluation of the capacity of evacuation sites under such snowy cold conditions, and publish our techniques and results. In this way, we are developing technologies to easily and quickly create socially useful information from a geographical perspective, and are continuing our research to contribute to the formation of the foundation for an advanced information society.

Research

Concrete is structurally hardened by binding rock (aggregate) through a hydration reaction between cement and water. As a structural material, concrete is intended to withstand loading and certain weather/environmental conditions, but these may cause cracking of the concrete, which may progressively deteriorate due to strong acids and other chemical reactions caused by erosion and materials from the atmosphere, seawater and groundwater that come in contact with it. To stably use the social infrastructure for a long period of time, it is important to be able to see inside the internal structure of concrete with “bug eyes” and find any abnormalities that have occurred.
With the pioneering “non-destructive integrated CT-XRD method,” the sample is irradiated with high-intensity X-rays from synchrotron radiation to selectively visualize 3D structures from transmitted monochromatic X-rays at 25 keV. Energy-dispersive X-ray diffraction is also performed in specific regions of interest through multiple slit operations to identify hydrates (portlandite, calcite, etc.), their alteration and aggregate minerals.

Research

In this study, we are constructing a mathematical algorithm for biomedical optical imaging based on the radiative transfer equation. Our goal is to develop an imaging technique with excellent image resolution that can be applied to biological tissues and body parts where conventional imaging based on mathematical models cannot be applied. Until now, the numerical computational burden of the radiative transfer equation has been enormous, limiting its applicability to small-sized organisms. In this study, we have succeeded in developing a highly accurate and computationally efficient light propagation model by coupling the radiative transfer equation and the photon diffusion equation. Optical imaging based on the developed light propagation model can be applied to various biological tissues and sites. Currently, we are working on applying the model to the optical diagnosis of thyroid tumors in the human neck and the in-vivo evaluation of optical property values in biological tissues.

Research

The system estimates the genres and information sources that a user prefers based on the user’s past information browsing history, and assesses the event information that the target user is interested in by referring to the browsing trends of users with similar interests. It also takes into account the geographic characteristics of the user and finally presents the information to him/her. The timing of information distribution is adjusted throughout the system so that the overall system performance can be improved.

Research

To conserve and manage local resources through resident participation, the “landscape” approach, which views the region from people's perspective, is very effective. We are developing research on people's and society's landscape perception, and conducting empirical research on how to utilize people’s place attachment in local resource management.
Environmental planning using health resorts (Kurort)
In Germany, medical insurance covers services at government-recognized recuperation and health resorts that make use of the natural environment such as hot springs, the sea, and the climate. In Japan, too, efforts are underway to create health resorts (Kurort) that combine health tourism with local health promotion.
Forest utilization as burial sites:
To utilize forest resources, we are conducting practical research on the development of forest burial sites in Japan, modeled after Germany’s examples. As a new method of managing forests, which account for 70% of Japan’s land area, we are promoting the creation of forest burial sites in various regions as a means of regional management in aging society.

Research

○ For geothermal resource development, which has been actively promoted in recent years, geothermal reservoirs are examined through base structure surveys. We have been investigating the basement structure through gravity surveys, precise seismic source distribution, and seismic velocity structure analysis.
○ For geothermal power generation, steam is produced and hot water is returned to the underground, but it is necessary to monitor the level of the geothermal reservoir to ensure the sustainable use of resources. We will examine the appropriate resource utilization volume through physical assessment of the subsurface fluid conditions using precise gravity measurements and crustal deformation observations.
○ The injection of high-pressure fluids into geothermal wells may induce noticeable tremors and cause problems. We will provide guidelines for appropriate and sustainable resource development by developing a method to evaluate the risk of induced earthquakes based on such parameters as the crustal stress state in the geothermal development area, surrounding faults, the characteristics of the seismic activity, and fluid injection volume.

Research

To accurately obtain the position of a user in a room or a moving object in real time, we have proposed a high-precision time reference point setting method called the phase-matching method (ranging error of 0.03 mm). Based on this technology, we have developed a smartphone users’ gesture recognition system and a robot tracking system. We have also achieved microsecond-order time synchronization using a camera-equipped mobile terminal and an original algorithm. The integration of LED modulation and terminal location information will allow us to distribute location-dependent information and conduct flickerless visible light communication using indoor lighting.

Research

An Al-base alloy with a melting point above 500°C was newly discovered as a latent heat storage material. By skillfully applying chemical conversion/oxidation treatment to the micro-particles of this alloy (approx. 20 μm or larger), we have succeeded in developing core (Al-base alloy) and shell (Al2O3) type latent heat storage microcapsules (Fig. 1). These microcapsules have high heat storage capacity of approximately five times that of solid sensible heat storage materials, and have excellent mechanical properties. Since the shell is made of Al2O3, it can also be treated as a ceramic particle. In other words, it is an epoch-making heat storage material of which the performance can be upgraded while maintaining the current use of ceramic sensible heat storage technology.

Research

We have found that homogeneous palladium nanoparticles can be obtained by treating palladium acetate with potassium tert-butoxide or sodium borohydride in the presence of alkynes (Fig.1). The nanoparticles can be stored in solution for longer than a year and are easy to handle in air. They exhibit excellent performance as hydrogenation catalysts and can efficiently synthesize cis-alkenes (2) and amines (4 and 6) from alkynes (1), organic azide compounds (3) and aromatic nitro compounds (5), respectively. They have excellent cis-alkene selectivity and functional group tolerance (no loss of the ketone, aldehyde, or benzylic hydroxy group, etc.). The catalytic activity is extremely high; the reaction proceeds quickly using only 1/1000 to 1/5000 equivalent of palladium of the substrate (raw material). It also has excellent economic efficiency and convenience, and we are examining the possibility of commercializing it in cooperation with companies.

Research

We are not only conducting the world's most advanced artificial intelligence research, but also promoting research in interdisciplinary areas and taking on the challenge of solving real-world problems. Specifically, in medical imaging research, we have collaborated with many medical institutions in Japan to build AI technology that surpasses human diagnostic accuracy. In medical and civil engineering research, we have built Explainable AI (XAI), which not only enables learning of small amounts of data, a challenge in AI research, but also enables explanations of judgment results, making the technology usable in the real world. In recent years, we have also developed human-centric AI technology that can make decisions like humans by introducing information strongly related to human interests, such as human brain activity and eye gaze data, into the AI learning process.

Research

To develop a new grout with low environmental load, we focused on minerals produced by living organisms in nature (biominerals), especially CPC, a major component of teeth and bones, and investigated the optimum conditions for CPC precipitation. We also conducted uniaxial compression tests on sand specimens solidified with CPC. In the CPC precipitation test, we have found that the precipitation volume tends to increase as the pH increases from weakly acidic to near neutral. This causes the uniaxial compressive strength of the CPC-solidified sand specimens to reach about 90 kPa, which is within the target range of 50 to 100 kPa for uniaxial compressive strength of sandy soil to prevent liquefaction. Electron microscopy of the specimens showed whisker-like CPC crystals (Fig. 1). These results indicate two possibilities of their usage: chemical grout using self-hardening property and biogrout using pH-dependent precipitation volume.

Research

The significant drag reduction in turbulent channels due to the addition of a small amount of long-chain polymers or surfactants that form rod micelles in water, is known as Toms effect. A model that simulates polymers with small dumbbell-shaped elements was constructed, and direct numerical simulation (DNS) of turbulent flow in a two-dimensional channel was performed using this model to reproduce Toms effect. It was shown that the discrete element has two mechanisms: one is a resistance reduction mechanism due to the longitudinal vortex damping, and the other is a resistance increasing mechanism due to the additional stress near the wall. Furthermore, by adding the effect of cutting the element to which a strong force is applied, we were able to reproduce the feature that drag reduction occurs in a specific Reynolds number range.

Research

The transport properties of porous materials such as concrete does not only depend on the porosity, but also on the spatial distribution of each phase. Therefore, the transport properties of HCP, which is a main component of concrete, was predicted. Figure 1 shows a cross section of HCP observed using a backscattered electron image, showing the distribution of each phase. We extracted each phase, calculated the autocorrelation function, and based on the results, distributed each phase in three-dimensional space to construct the three-dimensional spatial image model shown in Fig. 2. Figure 3 shows a comparison of the results of the diffusion coefficient calculated by the finite difference method and the measured values. The estimated and measured values agreed well with each other, even for different samples, indicating that the diffusion coefficients of hardened cement can be predicted using this model.

Research

Since the amount of data handled during image processing is generally huge, it is essential to optimize the system as a whole by combining hardware and software. In this laboratory, we are investigating the configuration of image processing systems by studying image processing algorithms and their implementations complementarily. One of the results of our research is real-time adaptive brightness correction of video images based on the Retinex theory (Fig. 1), which can adaptively correct the brightness of video images taken under conditions of large changes in illumination, such as backlighting, in real time. We are also working on high-quality image smoothing (Fig. 2) based on cost optimization, which is expected to be applied to image processing such as photo illustration, pre-processing of various image processes, brightness correction, and detail enhancement.

Research

We are researching technologies for the automatic recognition and modeling of objects and structures in indoor and outdoor environments from point clouds obtained by ground-based and vehicle-mounted 3D laser scanning systems, as well as basic point cloud data processing methods. The objects to be recognized and modeled include a wide range of arbitrarily shaped objects, rooms, pole-like objects such as utility poles and street lights, trees, road surfaces, and buildings. In addition to the technology of generating mesh models, polygon models, and CAD models from point clouds, we also conduct research on point cloud registration, segmentation, shape feature extraction, machine learning, and procedural object recognition that serves as the foundation for the technology. This technology enables detailed recognition and analysis of the environment and structures, maintenance and management, various simulations and improvement plans using 3D models that faithfully reflect the current state.

Research

The town of Kamishihoro in Kato-gun, Hokkaido, like other municipalities in Hokkaido, is facing a rapid population decline: from 10,309 in 1965 to about half that number in 2010. It is estimated that the population will decline to 3,222 by 2040. In 2012, taking this situation into consideration, the city established 10 themes for the creation of a city with a population of 5,000; and the first of these was to create a grand design for the layout of public facilities.
The reorganization of public facilities in urban municipalities is generally implemented to ease financial pressures by controlling the number of facilities. However, Kamishihoro Town has different challenges and objectives. We are exploring the question of that kind of affluent lifestyle that can be achieved in a small town with a population below 10,000, and the role of public facilities to this end.

Research

In Southeast Asia, there are many archaeological sites such as the Angkor complex (Cambodia) and Borobudur (Indonesia). Faced with political turmoil and crises caused by natural disasters such as the Sumatra earthquake and tsunami (2004), each country has been working to preserve and utilize these sites. Tourism used to be considered dangerous as it would have a negative impact on the sites, but since the adoption of the International Charter on Culture and Tourism in 1999, it has come to be seen as an essential part of cultural heritage preservation. For example, in the Angkor Complex, which attracts more than 2 million tourists a year, the tourism industry has become an important means of earning foreign currency at the national level, and the revenue from tourists is used for the conservation of the vast ruins. On the other hand, the balance between the ever-increasing number of tourists and the preservation of the monuments has become increasingly complicated due to the local environment, economy and other issues.

Research

The quantum key distribution technology has passed the proof‐of‐principle phase, and research is now under way with an eye on its practical application. Since this is a technology to realize the ultimate confidential communication, field tests and other researches on it are conducted worldwide. In our laboratory, we are examining both theoretical and implementation-related aspects on quantum key distribution. In the real world, things do not always go according to the theory, and experimental results sometimes differ from those expected in theory. Our goal is to examine these discrepancies and quantitatively guarantee the security of cryptographic keys produced on real devices. To this end, we are conducting research to fill the gap between the theoretical studies and the actual device development. We believe that this research will open the way to measure and evaluate the behaviors of the actual quantum devices, and finally to realize practical quantum systems, which will contribute to future quantum networks.

Research

As telecommunication devices increase in capacity and become more sophisticated, semiconductor devices are becoming more and more integrated. However, there is concern that cosmic ray neutrons may cause an increase in soft errors, such as bit information upset and operation confusion. Therefore, in collaboration with NTT, we have reproduced soft errors using a compact electron accelerator-driven neutron source to create a place to develop countermeasure technologies in advance. This enables the advance prediction of the failure rate in the natural environment, the detection of errors and verification of operational measures, which will lead to improved reliability of the equipment.
The feature of this technology is the use of a compact accelerator-driven neutron source. In the past, large-scale accelerator-based neutron sources were required, and it was difficult to secure sufficient test time and experimental space. However, through our research, we have demonstrated that it is possible to conduct sufficient tests even in a facility with a neutron intensity of several million times that in nature.

Research

Hokkaido University’s laboratory facilities, where small accelerators are used, have a history of nearly half a century, and are attracting worldwide attention as pioneering facilities. We mainly produce pulsed neutron beams, and the transmission spectra obtained using these beams enable us to map information on crystal structure, microstructure, internal stress and temperature on a two-dimensional real image as a distribution map of the entire sample. We also use X-ray CT which can measure the three-dimensional structure of the inside of an object, and analyze the combined results from neutrons and X-ray studies to synergistically understand the interior information of an object. In the figure, shown as synergistic imaging based on information from neutrons and X-rays, information on elements that cannot be individually obtained is mapped on the inside structure shown on the X-ray CT image. X-ray CT shows the presence of wires in an Al cylinder, but when neutron information is added, we can see that each wire is a different material.

Research

Instead of treating archaeological sites as an annoyance for development work, we will change their value as local resources for the people living in the area and as cultural resources shared by all human beings. For this purpose, a part of the archaeological sites will be excavated in a planned manner and will be maintained and preserved as a "satellite" of the “ecomuseum.” An ecomuseum is a museum that does not require a roof or walls. Satellites are open-air exhibits. While working with local people to develop and preserve the archaeological sites as historical heritage, we are proud to live in the area and participate in the ecomuseum activities as hosts. The planned excavation of the site will be carried out in cooperation with local people and the board of education as part of the university's “Archaeology Practice” educational program. We find it meaningful to practice part of the university education in the local community, the practice of which then becomes the practice of ecomuseum activities as such.

Research