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