- Home
- Researcher
- "A" Researcher
"A" Researcher: 14
Life Sciences
Information and Communication
Nanotechnology / Materials
Manufacturing Technology
Human and Social Sciences
Energy
Environment
Tourism / Community development
Arctic Research
Social Infrastructure
Open Facilities
View All
View Detail-
Portable Liquid Chromatograph
Battery-powered, ultra-light, ultra-compact chemical analyzer
Using proprietary technology, we have miniaturized the pump, column and detector, all key components of liquid chromatography, realizing a compact, B5 size, lightweight and portable liquid chromatograph weighing 2 kg. This allows us to instantly obtain analysis results on the spot.
Research
The pump we have developed for liquid chromatography is based on electroosmotic phenomena and can operate for a long time on dry batteries. Since there is no mechanical drive, it is extremely compact and lightweight, and does not generate pulsating flow. Using microfabrication technology, the column and (electrochemical and UV) detectors are mounted on small amounts of substrate, the size of a business card. Conventional packing materials are used for the column, so the same analysis conditions as before can be applied directly without modification. The electrochemical detector uses a uniquely developed comb-shaped electrode. Although small in size, it has comparable sensitivity as conventional detectors. Liquid chromatographs currently used as the main instrument for chemical analysis are large and heavy, limiting their use to specific locations in the laboratory, but the instrument we have developed can easily be used anywhere. The amount of solvent used can also be reduced to 1/100 to 1/1000 of conventional detectors.
Akihiko Ishida Assistant ProfessorDoctor of Engineering -
Changing the Region through Border Tourism
Nemuro, Soya, Okhotsk
The Boundary Research Unit (UBRJ) established at the Center in 2013 is a unique organization in Japan that leads border studies in Japan and abroad. It is composed of faculty members from the humanities and social sciences and museums at Hokkaido University. Recently, we have been working on the promotion of tourism in border regions.
Research
The 12th International Scientific Meeting on Border Regions in Transition was held in Fukuoka and Busan in November 2012. We took a jetfoil from Hakata to Izuhara (Tsushima), and after a bus tour of the famous sites, we headed north to Hitakatsu and from there to Busan. The success of this project attracted attention both at home and abroad, and we started a border tourism project with a regional think tank and related local governments based on the belief that “borders can also be a tourism resource in Japan.” Cross-border tourism between Tsushima and Busan, Wakkanai and Sakhalin, and “border tourism without crossing borders,” involving traveling overland from Nemuro to Wakkanai, have been widely covered by the media. For more information, please visit the following URL: http://src-h.slav.hokudai.ac.jp/ubrj2/projects/border-tourism/
Akihiro Iwashita Professor -
Security Certification Technology for Quantum Key Distribution Devices
Experimental certification of ultimate cryptographic security
Using quantum key distribution, we can share cryptographic keys via optical communication while maintaining a high level of secrecy, no matter how the technology advances in the future. Through our research, we offer technologies to experimentally guarantee the security of quantum cryptography using an actual device to realize its practical application.
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.
Akihisa Tomita Professor -
Research on the Conservation and Utilization of Cultural Heritage and Tourism
Planning and implementation of international cooperation projects on cultural heritage in Southeast Asia
We are conducting research on the relationship between the conservation and utilization of cultural heritage and tourism in Southeast Asia, with special focus onmonuments. Based on the results of our research, we collaborate with other organizations to implement international cooperation on cultural heritage.
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.
Akiko Tashiro Associate Professor -
High-efficiency Semiconductor Solar Cells
New-type solar cell consisting of a multi-striped semiconductor with orthogonal photon-photocarriers that was coupled to a waveguide.
Temperature rise and device degradation are suppressed by simultaneous optimization of light absorption and photocarrier collection, as well as photoelectric conversion over the entire solar spectrum by multiple semiconductor stripes. This leads to the realization of a highly efficient 2-dimensional PhotoReceptoConversion Scheme (2DPRCS).
Research
In conventional solar cells, there is a trade-off between carrier collection and the number of absorbed photons because the photo carrier migration direction and the light travel direction are parallel. Based on the orthogonality between the carrier migration direction and the light travel direction, it was possible to optimize both the light absorption and the carrier collection efficiency. Since the sunlight is sequentially photoelectrically converted from high- to low-energy components over the entire spectrum, thermal dissipation is minimized and high efficiency can be achieved. A waveguide type light collection system with a light wave direction conversion membrane can realize a photovoltaic system that is resistant to diffuse light. By preventing high-energy photons from entering the mid-gap and narrow-gap semiconductors, bond degeneration can be prevented and the life of the device can be extended. It is possible to realize the ultimate concentrator solar cell system, which is strong even in cloudy weather, has high conversion efficiency close to the thermodynamic limit, and is highly reliable.
Akira Ishibashi Professor -
Low-temperature Nitridation Method Using Sodium Amide
Nitride and oxynitride synthesis without using ammonia gas cylinder
This is a method used to convert oxides and other materials into nitrides and oxynitrides at low temperatures (300°C or less) by using a sodium amide melt to trigger a reaction with a highly concentrated and active nitrogen source. Nitrides and oxynitrides can be synthesized without having to prepare toxic ammonia gas cylinders.
Research
This is a new method for nitridation of oxides at low temperatures (300℃ or less). Conventional nitridation methods require the installation of toxic ammonia gas cylinders and toxic ammonia gas recovery facilities, and also use a large amount of ammonia due to the low ammonia gas usage rate. With the present method, the use of sodium amide as a flux minimizes the use of toxic ammonia and makes it possible to obtain oxynitride and nitride nanocrystals at low temperatures. Since sodium amide is a solid nitrogen source, it eliminates the need to install ammonia liquid cylinders. We have also discovered a method to synthesize oxynitrides by mixing chloride and sodium amide through an instantaneous temperature-programmed reaction.
Akira Miura Associate Professor -
Mathematical Analysis Techniques for Information Science and Engineering
System identification, design and inverse problems
Exploration of methodologies and development of applied technologies to solve problems in information science and engineering related to system identification and design and estimation of unknown objects
Research
In the field of information science and engineering, many problems appear, such as the problem of designing a mathematical system that provides a desired result, the problem of identifying a mathematical model that gives a given input and output, and the inverse problem of estimating unknown inputs from a system and observations. When dealing with these problems, by dividing the analysis into conditions specific to each problem and mathematical models independent of each problem, it becomes possible to theoretically determine the performance and limitations, and to also expand the analysis horizontally to problems that can be described by similar mathematical models. With this unique approach, we have developed various methodological constructs and application techniques in machine learning problems including image and color restoration, separation of individual sounds in acoustic signals, pattern recognition, and sampling theory. By applying our methodology to today's rapidly developing and diverse measurement technologies, we expect to develop a variety of application techniques based on theory.
Akira Tanaka Professor -
Numerical Simulation of Flow and Heat Transfer
Modeling and Simulation of Turbulent Drag Reduction Flow by Surfactant
Modeling and simulation of turbulent drag reduction is performed by adding a surfactant to clarify the resistance-reducing mechanism. Simultaneously, heat transfer analysis is performed to investigate the flow and heat transfer characteristics in detail.
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.
Akiyoshi Kuroda Associate Professor -
Modern and Contemporary Economic History of Hokkaido
Mainly in central Hokkaido
The term “Hokkaido economy” is still associated with “backwardness” and “primary industry.” However, if we look at the history of Hokkaido in modern times, we can see remarkable progress in urban development, which has undergone an expansion and transformation unparalleled in Japanese economic history, especially in Sapporo and the central part of Hokkaido.
Research
Since Hokkaido is an island, new ports have continuously been built and port cities developed, and the central ports have changed with the times. It is said that Hakodate and Otaru were the two largest commercial centers in Hokkaido during the Meiji era (1868-1912), followed by the rapid growth of Muroran and Kushiro during the wartime period. After the war, the port of Tomakomai was opened, and in 1982, the Ishikari Bay New Port was opened. All of these were planned during the war but actually constructed after the war. With the centralization of Sapporo, port functions became centralized in Tomakomai. Although Otaru is still alive and well as a tourist city, the Ishikari Bay New Port has surpassed Otaru as far as port functions are concerned. These changes in the major ports are backed by transformation of Hokkaido’s industries. We are researching the economic history, which is of the island of Hokkaido from the perspectives of logistics and industries, particularly on how it is related to the present.
Asahiko Shirakizawa Professor -
Vertical Takeoff and Landing Type Unmanned Aerial Vehicle
An unmanned aircraft that can fly at high speed like an airplane and hover in midair like a helicopter
We have developed a vertical takeoff and landing type unmanned aerial vehicle that can hover like a helicopter while flying at high speed by obtaining lift with its wings like an airplane. It is expected to be used, for example, to quickly fly to a stricken area in the event of a disaster and to photograph the area while hovering in the sky.
Research
There are expectations of the industrial application of unmanned aerial vehicles, as DHL and Amazon are performing tests on delivery by unmanned aircraft. These unmanned aircraft are helicopter-type vehicles called multicopters. Since they have fixed wings and fly like airplanes, they move efficiently and at a high speed, and can fly farther than ordinary multicopters with the same battery.
Atsushi Konno Professor -
Optical Complex Amplitude Measurement Technology
Enabling the detection of spatial phase information of light: Technology for seeing the invisible
This technology enables precise detection of optical phase distribution in a single measurement without spatial completion error by using two sensors and a polarizing optical element, and is expected to have a wide range of applications such as 3D image measurement, 3D tomography, digital phase conjugation, 3D optical memory, and spatial mode optical communication.
Research
In holographic diversity interferometry, multiple image sensors are arranged in combination with a polarizing optical element to enable precise detection of optical phase distribution in a single measurement without spatial completion error. We have developed an interferometric optical system using two image sensors and have greatly improved the measurement algorithm to achieve highly accurate phase measurement and enable 3D information processing using the measured phase distribution data. This technology can be applied directly to the acquisition of 3D optical information, optical tomography by digital phase conjugation, and 3D optical memory. In this research, we have also succeeded in developing a reference light-free phase detection system that filters the signal light spatially filtered and re-interacts with the signal light. This is expected to find applications in next-generation ultrahigh-speed optical communication systems using spatial modes and in the field of remote sensing.
Atsushi Okamoto Associate Professor -
Research on Internal Communication in Organizations
Communication in risk and strategic systems
I am interested in the risk communication that is formed within management organizations. Risk can be broadly classified into pure risk and dynamic risk, and I am examining how these elements shape communication within organizations and define individual and group behavior.
Research
The primary purpose of my research is to identify the unique communication phenomena that form within organizations. In my research on pure risk, I explored internal/external organizational public relations, especially as pertaining to product accidents and the internal risk communication in organizations handling hazardous materials. I believe that communication that is created/disturbed/diffused/structured within an organization and that has some kind of inherent meaning/value for the organization will lead to novel organizational strategies, and that is what characterizes my research and makes it unique. In this regard, I have recently been examining how social organizations (e.g., photography) are organized and the intentions of it.
Atsushi Tsujimoto Professor -
Glowing Plankton
GFP and luciferase in copepods
Marine organisms include various bioluminescent creatures. We have identified a green fluorescent protein (GFP) and a secreted luciferase (luminescent enzyme) from copepods, the most dominant plankton species.
Research
Zooplankton serves as energy transmitters in marine ecosystems, passing basic production to higher organisms. The dominant zooplankton species in the Arctic Ocean are copepods, most of which have a lifespan of one year or less, but their samples can be preserved semi-permanently with formalin fixation, making them an ideal taxonomic group for assessing the interannual variability in biological production in the region. Some species of copepods are also bioluminescent. It is thought that they emit light when they are about to be predated upon in dark waters, and use it to distract predators. We have identified a fluorescent protein (GFP) and a luciferase (luminescent enzyme) from copepods.
Atsushi Yamaguchi Associate Professor -
Recommendation Techniques Using the Bandit Method
Online learning technology that maximizes cumulative gain while acquiring knowledge
We are researching a recommendation method that maximizes the user's cumulative satisfaction, not only by recommending items that the user may prefer (use of knowledge), but also items that may provide more information about the user's preferences (acquisition of knowledge) in a balanced manner.
Research
In today's internet society, recommendation technology, if it works well, can benefit both the provider and the receiver of the service. A recommendation service is not a one-time event, but an iterative process with feedback each time, and the feedback only concerns the items that are recommended. Therefore, to increase the accuracy of subsequent recommendations, it is not only important to recommend items that the user is likely to like based on the feedback history (knowledge utilization), but also items from which the user is likely to acquire more information (knowledge acquisition). The Bandit method attempts to maximize user satisfaction by balancing the use and acquisition of knowledge. We are developing a recommendation system using this method.
Atsuyoshi Nakamura Professor
