September 2024 Vol. 22 No. 9

View from the Top

• Kei Ikeda, Senior Vice President, Head of Technology Planning, NTT Corporation

  

  Abstract
  The NTT Group is committed to solving social issues as a leading corporate group in the telecommunications business with a public responsibility. Its goal is to create a well-being society by building the world’s most-advanced and sustainable social systems and infrastructures. We interviewed Kei Ikeda, NTT senior vice president, head of technology planning, who also serves as the co-chief artificial intelligence officer and chief information officer, about the NTT Group’s technology strategies and his beliefs as a top executive.

Front-line Researchers

• Kunio Kashino, NTT Fellow, NTT Communication Science Laboratories

  

  Abstract
  Announced in November 2020, NTT’s Medical and Health Vision states that the company will strive to put biological simulations using bio-digital twins (BDTs) into practical use to make effective use of medical resources, alleviate physical constraints of medical resources, provide continuous care from prevention to post-treatment, and provide precise care personalized for each individual. A BDT is a digital representation of a living organism, and the key to creating a BDT is how to express (quantify or symbolize) the functions of the living organism—and the physical and chemical mechanisms behind them—as digital information. We interviewed NTT Fellow Kunio Kashino of NTT Communication Science Laboratories, who has taken the challenge of creating a BDT, about the use of artificial intelligence in the biomedical field, stimulation and awareness in collaborative research across different disciplines, and his thoughts on the importance of striking a balance between what should be done and how it should be done.

Rising Researchers

• Makoto Nakatsuji, Distinguished Researcher, NTT Human Informatics Laboratories

  

  Abstract
  The artificial intelligence (AI) field offers a variety of services such as chatbots and image generation, including NTT’s proprietary large language model “tsuzumi.” In the midst of the dizzying pace of change, one of NTT’s goals is to create a world in which AI grows autonomously and cooperates with humans. NTT Distinguished Researcher Makoto Nakatsuji believes that building such a world “enables productive endeavors that are more creative,” which are very different from conventional AI-based endeavors. In this interview, we asked him about his current project, “building human-AI cooperative infrastructure with generative AI agents.”

Feature Articles: Challenging the Unknown: Mathematical Research and Its Dreams

• A Mathematical World Woven by Number Theory, Algebraic Geometry, and Representation Theory

  

  Abstract
  Through basic research in mathematics, the NTT Institute for Fundamental Mathematics aims to enrich the “fountain of knowledge” that nourishes science and technology. In this article, we first provide an overview of the research being carried out at the Institute then introduce the Institute’s core research areas: number theory, especially arithmetic dynamics; algebraic and arithmetic geometry; and representation theory and automorphic forms.

• Arithmetic Problems in Dynamical Systems

  

  Abstract
  In discrete dynamical systems, the ultimate goal is to understand the asymptotic behavior of all points under iterated compositions of a certain transformation (self-map) of a certain space. In arithmetic dynamics, the asymptotic behavior of points with coordinates of arithmetic interest (algebraic numbers or p-adic numbers) is examined. In connection with arithmetic dynamics, some problems are reduced to the determination of rational points on curves. This article introduces the issues in arithmetic dynamics related to these problems.

• How Number Theory Elucidates the Mysteries of Complex Dynamics—Viewed through Non-Archimedean Dynamics

  

  Abstract
  The theory of complex dynamics is an area of pure mathematics. Even though the theory of dynamical systems belongs to analysis, it is studied in relation to various fields of mathematics, including algebra and geometry. I study it using the theory of non-archimedean numbers from number theory, which seems distant from dynamics. In this article, we discuss how attractive these theories are.

• Motives—Abstract Art of Numbers, Shapes, and Categories

  

  Abstract
  In arithmetic geometry, we study problems of numbers by transforming them into problems of shapes called algebraic varieties (geometric objects). Cohomology theories extract the information of algebraic varieties as linear data. Various cohomology theories have been developed to study different aspects of algebraic varieties. However, it is widely believed that there is a universal theory called the motive theory, which unifies these cohomology theories. This article gives an overview of the motive theory and presents attempts by the author and his collaborators to generalize it.

• Representation Theory and Combinatorics Arising from Determinants

  

  Abstract
  Originating from the unified treatment of probability distributions, the α-determinant is a one-parameter interpolation of the determinant and permanent of a matrix. While it generally does not have the invariance properties of the determinant, the irreducible representations of the associated general linear (Lie) groups define interesting invariants that unveil a new and rich mathematical theory with abundant unsolved problems, related to symmetric functions, representation theory, combinatorics, number theory, probability and other areas.

• Symmetry and Representation Theory of Lie Groups and Lie Algebras

  

  Abstract
  Representations of Lie groups are abstractions of continuous symmetries of linear spaces. By considering their differentials (linear approximations), we obtain representations of Lie algebras. These are regarded as generalizations of the Fourier analysis and important tools not only in mathematics but also in physics. In this article, I present fundamental and important examples on representations of Lie groups and Lie algebras and present some of my latest results.

• Modular Forms and Fourier Expansion

  

  Abstract
  Fourier analysis is an indispensable technology, but so is mathematics. In this article, we review the history of modular forms and give an overview of the relationship among representation theory, Fourier analysis, and modular forms. The explanation of difficult terms is confined to footnotes, and we focus on the relationship between the concepts. Finally, we discuss the remaining difficulties in the modern theory of modular forms, challenges, and the author’s research.

• Light-matter Interaction and Zeta Functions

  

  Abstract
  Knowledge of the partition and spectral zeta function of a quantum system is fundamental for both physics and mathematics, and the positions these functions occupy in their respective fields share a common philosophy. In this article, we describe the number theoretic structures hidden behind light and matter interaction models, focusing on the partition function and special values of the spectral zeta function, highlighting how modern mathematical research is involved.

Regular Articles

• Digital Longitudinal Monitoring of Fiber-optic Link Using Coherent Receiver

  

  Abstract
  In fiber-optic communication systems, it is crucial for operators to accurately monitor various physical parameters along optical links to fully leverage the potential transmission capacity and conduct fault analysis. Digital longitudinal monitoring (DLM) has been intensively studied for its capability of monitoring various physical parameters, such as optical power, distributed along the fiber-longitudinal direction by solely processing signals received at coherent receivers. In this article, the fundamentals and recent advances in DLM are reviewed, including working principles, spatial resolution, and key experiments demonstrating its feasibility for use in operations.

• Collaborative Business Navigation Platform That Comprehensively Supports Work of Operators

  

  Abstract
  NTT Access Network Service Systems Laboratories has long been developing technologies that contribute to more-efficient operations on personal computers and other information devices. We have implemented a collaborative business navigation platform as a new technology to continue this trend. Using this platform makes it possible to easily develop digital transformation (DX) tools suited to diverse work environments and operator roles. This article discusses the functions of the collaborative business navigation platform and the use cases of DX tools by using this platform.

• Work-improvement-support Technology that Supports Wide-ranging Implementation and Application of Digital Transformation Measures

  

  Abstract
  To make operations of an organization digital, i.e., digital transformation (DX), companies and local governments are promoting on-site efforts to improve business efficiency using digital technology and the implementation of measures by DX-promotion departments. To further enhance the effectiveness of DX promotion, it is necessary to create a DX cycle in which workers in the field and DX-promotion departments cooperate to efficiently and accurately implement effective DX measures over a wide area. The work-improvement-support technology developed by NTT to meet this necessity is introduced in this article.

Global Standardization Activities

• ITU-T SG16 Meeting Report

  

  Abstract
  The International Telecommunication Union - Telecommunication Standardization Sector (ITU-T) Study Group 16 (SG16) meeting was held in Rennes, France, in April 2024 with online participation (hybrid). NTT Group made a proposal to Question 8 to initiate a new work item on “first-person transfer immersive live experience,” which enables users to share (feel) the sensation of the performer at a remote event site (e.g. the piano player in a music concert). This article mainly reports on the discussion and result of Question 8.

External Awards/Papers Published in Technical Journals and Conference Proceedings

• External Awards/Papers Published in Technical Journals and Conference Proceedings