TOKYO, June 23, 2021 /PRNewswire/ -- University of Electro-Communications publishes the June 2021 issue of UEC e-Bulletin
June 2021 issue of UEC e-Bulletin
The June 2021 issue of the UEC e-Bulletin includes a video profile of UEC Assistant Professor Daisuke Nakane where he describes his recent research on "How and why do bacteria move".
The Research Highlights are, 'Bacteria in the spotlight: Bacterial community exhibits only counterclockwise movement,' Daisuke Nakane; 'Innovative building blocks for the quantum internet: All fiber platform for quantum photonic processing on tapered optical fibers,' Kali Nayak; and 'Efficient & reliable data processing for scalable Internet of Things: Innovative amplify-and-forward-based AirComp,' Suhua Tang.
The Topics section is an interview with Lu Jin, Associate Professor at the Department of Informatics, UEC Tokyo, who offers insights into mathematical modelling of reliability engineering.
News and Events features the launch of the 'Joint demonstration experiment on visualizing carbon dioxide concentration inside Chofu City Hall with eight IoT sensors' on 1 June
Efficient & reliable data processing for scalable Internet of Things: Innovative amplify-and-forward-based AirComp
One of the critical issues for the proliferation of Internet of Things (IoT) is the collection and computational analysis of wireless data from huge networks of smart sensors being implemented in applications that include smart transportation and cities. Recently, the technique of over-the-air computation (AirComp) has been proposed as an integrated approach for collection and processing of data from sensor networks transmitting Big-data simultaneously. Notably, although this method is efficient, it requires that all signals from nodes arrive simultaneously at the sink, aligned in signal magnitude so as to enable an unbiased estimation. However, for nodes far away from the sink with low channel gains, it is not possible to avoid misalignment in signal magnitude.
Now, Suhua Tang and colleagues at University of Electro-Communications, Tokyo, University of Science and Technology, China, and Xi'an Jiaotong University, China, describe their solution to the misalignment problem using the amplify-and-forward (AF) based relay mechanism.
In their paper, Tang and colleagues first present the general relay model for AirComp, and investigated the possibility of using a simple relay (SimRelay) approach in which a node either directly transmits its signal to a sink or via a relay node, but not both. They emphasize that, "relay transmission power increases with the number of nodes that use the relay node."
The researchers also proposed a coherent relay (CohRelay) approach, in which a node can divide its power to transmit its signal to both the relay and the sink, and the replicas of its signal are coherently combined together at the sink. They also discuss the tradeoff between computation error and transmission power.
The CohRelay approach greatly reduced the computation error, as well as reducing the relay transmission power and the overall transmission power, which is a major step forward towards the practical applications of AirComp.
Caption: Relay for AirComp, an analogy to a conventional relay network.
Suhua Tang, Huarui Yin, Chao Zhang, and Sadao Obana, Reliable over-the-air computation by amplify-and-forward based relay, IEEE Access, vol. 9, pp. 53333-53342, Apr. 2021.
Innovative building blocks for the quantum internet:
All fiber platform for quantum photonic processing on tapered optical fibers
Research on quantum photonics is focused on the coherent control of individual quanta of light known as photons. Such control of light is an important step towards the realization of optical quantum networks and ultimately the so-called quantum internet.
Notably, single photons can be efficient carriers of quantum information, and they travel at the speed of light incurring the minimal of interaction with the medium through which they move. However, these same physical characteristics lead to difficulties in isolating (generation) and controlling (storage/retrieval/switching) single photons.
A solution to this problem is the development of means to control photons using atomic media. In this approach, one key requirement is to be able to confine atoms and photons to subwavelength dimensions, that is, within a single atom absorption cross-section to realize efficient light-matter interaction at the single quanta level. Therefore, there has been increasing interest in the strong confinement of photonic modes in nanophotonic waveguides and resonators that exhibit quantum electrodynamics (QED) effects.
Now, Kali Prasanna Nayak and colleagues at the University of Electro-Communications, Tokyo, are developing a unique all-fiber platform for quantum photonics applications using tapered subwavelength diameter waist optical nanofibers.
The key feature of the UEC optical nanofiber technology is that the optical field is tightly confined in the transverse direction while propagating over long distances as a guided mode and enabling strong interaction with the surrounding medium in the evanescent region. This characteristic has led to unique possibilities for manipulating single atoms (solid-state quantum emitters) and fiber-guided photons. Furthermore, implementing even moderate longitudinal confinement in nanofiber cavities has enabled the strong coupling regime of cavity QED where coherent light-matter interaction can be realized at the single quanta level.
Based on their achievements to-date, Nayak and colleagues are developing both quantum interfaces between trapped (laser-cooled) single atoms and fiber-guided photons using photonic crystal nanofiber cavities, and fiber-coupled quantum light sources using hybrid systems of single quantum dots deposited on nanofibers. These fiber-coupled quantum photonics platforms show promise as building blocks for optical quantum processors and can be easily integrated into optical quantum networks.
Caption: Schematic diagram of a nanofiber-based quantum interface.
Kali P. Nayak et al., Count Estimation with A Low-Accuracy Machine Learning Model, Nanofiber quantum photonics, J. Opt. 20, 073001 (2018).
Digital Object Identifier (DOI): 10.1088/2040-8986/aac35e
Bacteria in the spotlight: Bacterial community exhibits only counterclockwise movement
The collective motion of self-driven particles is a fascinating area of research in physics and biology. In the case of bacteria, macroscopic behavior emerges through the movement of millions of bacterial cells self-propelled by flagellar rotation.
Here, Daisuke Nakane and colleagues report on the observation of a new mode of collective motion in non-flagellated soil bacterium known as Flavobacterium Johnsonian.
The researchers discovered that when bacterial cells were spotted on an agar plate with a low level of nutrients, the bacterial community exhibited vortex patterns that spontaneously appeared as lattices and integrated into a large-scale circular plate.
Notably, the large-scale circular plate exhibited unidirectional rotation in a counterclockwise manner without exception.
Nakane and his colleagues postulate that "this behavior might be an efficient strategy for cells of this species to find nutrients."
Link to Figure: http://www.ru.uec.ac.jp/topics/assets_c/202106/img3.jpg
Caption: Vortex patterns of bacteria
Daisuke Nakane et al., Large-scale vortices with dynamic rotation emerged from monolayer collective motion of gliding Flavobacteria, Journal of Bacteriology 203, e00073-21, (2021).
Researcher Video Profiles
Daisuke Nakane, Assistant Professor, Department of Engineering Science, UEC Tokyo.
How and why do bacteria move?
Here, Daisuke Nakane describes his research interests and recent results on how and why bacteria move.
It is well known that bacteria are one of the simplest forms of life on Earth. They live everywhere, and have a great impact on our lives, including health, agriculture, and environment.
"Bacteria are too small to be seen directly," says Nakane. "My research is focused on visualizing bacterial cells and their biological motion using optical microscopy to understand their behavior on a molecular level."
Insights into modern reliability engineering
Lu Jin, Associate Professor at the Department of Informatics, UEC Tokyo
"My research is based on reliability engineering," says Lu Jin, an associate professor at the Department of Informatics, UEC Tokyo. "I am working on maintenance planning to study a wide range of systems for ensuring the safety and security of our society. The interest of my research is developing decision-making models for realizing more flexible and efficient maintenance plan while maintaining high reliability and safety."
Jin is developing decision-making models for systems focused on optimizing problems for maintenance plans such as periodic maintenance and condition monitoring maintenance.
Specifically, Jin wants to reduce maintenance costs while maintaining reliability levels by dynamically adjusting and controlling maintenance plans based on monitoring information on operating systems. A maintenance plan that uses the Markov decision process as the core model, takes into consideration the effects of direct and indirect measurement of system deterioration, measurement accuracy, changes in the operating environment, and so on, and yields a trade-off between maintenance costs and failure losses.
News and Events
Joint demonstration experiment on visualizing carbon dioxide concentration inside Chofu City Hall with eight IoT sensors
From 1 June 2021, the University of Electro-Communications (UEC Tokyo) and Chofu City plan to jointly carry out a demonstration experiment to visualize the carbon dioxide concentration in Chofu City Hall and maintain good ventilation as part of an industry-academia-government collaboration.
Visualized image of carbon dioxide concentration (composite photo)
The demonstration will utilize high-precision compact carbon dioxide sensor developed by the Tanaka-Ishigaki Laboratory (Department of Informatics) and Yokogawa Laboratory (Info-Powered Energy System Research Center) at UEC Tokyo.
About the University of Electro-Communications
The University of Electro-Communications (UEC) in Tokyo is a small, luminous university at the forefront of pure and applied sciences, engineering, and technology research. Its roots go back to the Technical Institute for Wireless Commutations, which was established in 1918 by the Wireless Association to train so-called wireless engineers in maritime communications in response to the Titanic disaster in 1912. In 1949, the UEC was established as a national university by the Japanese Ministry of Education and moved in 1957 from Meguro to its current Chofu campus Tokyo.
With approximately 4,000 students and 350 faculty members, UEC is regarded as a small university, but with expertise in wireless communications, laser science, robotics, informatics, and material science, to name just a few areas of research.
The UEC was selected for the Ministry of Education, Culture, Sports, Science and Technology (MEXT) Program for Promoting the Enhancement of Research Universities as a result of its strengths in three main areas: optics and photonics research, where we are number one for the number of joint publications with foreign researchers; wireless communications, which reflects our roots; and materials-based research, particularly on fuel cells.
SOURCE University of Electro-Communications