Friday, Apr. 21st, 2023 at 16:45-18:15
The URL of Zoom will be announced via the faculty’s mailing list 3 days before the colloquium.
The lecture material will be available in PandA at 16:15 on the day of the colloquium.
Dr. Takuya YASUI
Innovation by Design and Technology Co-Optimization
Although the technology scaling of the logic CMOS process tends to slow down, it is still in progress even now in the single-digit node era. It has been realized that the performance-power-area (PPA) is continuously migrated by Design Technology Co-Optimization (DTCO). In particular, Standard Cell are extremely important to achieve the full scale node scaling from N5 to N3. In this talk, FinFlex Technology which TSMC developed new standard cell architecture will be introduced.
Friday, May 19th, 2023 at 16:45-18:15
The URL of Zoom will be announced via the faculty’s mailing list 3 days before the colloquium.
The lecture material will be available in PandA at 16:15 on the day of the colloquium.
Prof. Tasuku HIRAISHI
A Parallel Language with Backtracking-based Load Balancing for Irregular Applications
When we implement parallel programs for high-performance computing environments such as computing clusters or supercomputers, the issue of load imbalance is often encountered, especially for irregular applications, which are difficult to divide into subproblems with approximately equivalent loads. Task-parallel languages are often used to implement such applications, which enable dynamic spawning of tasks to be automatically assigned to workers. We are currently developing a task-parallel language called Tascell that employs a unique dynamic load balancing mechanism called backtracking-based load balancing. In Tascell, a worker initially chooses not to spawn a task and instead performs sequential computations. When a worker receives a task request, it spawns a task as if it had made a different choice in the past. In this presentation, I will introduce the design and implementation of Tascell, as well as its applications, such as graph mining and hierarchical matrix (H-matrix) calculations.
Friday, Jun. 16th, 2023 at 16:45-18:15
The URL of Zoom will be announced via the faculty’s mailing list 3 days before the colloquium.
The lecture material will be available in PandA at 16:15 on the day of the colloquium.
Akihiro Suda
The internals and the latest trends of container runtimes
Containers are a set of various lightweight methods to isolate filesystems, CPU resources, memory resources, system permissions, etc. Containers are similar to virtual machines in many senses, but they are more efficient and often less secure. This talk roughly consists of the following three parts:
1. Introduction to containers and how they spread in the last decade
2. Internals of container runtimes: namespaces, cgroups, capabilities, seccomp, etc.
3. Latest trends: Non-Docker containers, User Namespaces, Rootless Containers, Kata Containers, gVisor, WebAssembly, etc.
Friday, July 21st, 2023 at 16:45-18:15
The URL of Zoom will be announced via the faculty’s mailing list 3 days before the colloquium.
The lecture material will be available in PandA at 16:15 on the day of the colloquium.
Prof. Mirai Ikebuchi
Assistant professor at Dept. of Communications and Computer Engineering
Mirai Ikebuchi received a PhD degree in computer science from Massachusetts Institute of Technology in 2021. Then she moved to National Institute of Informatics in Japan as a postdoctoral researcher, and obtained the current position on April 2023. She works on programming languages, software verification, and mathematics around them.
Introduction to Proving the Correctness of Programs
There are several ways to make sure that a program is correct. One of the most commonly employed way is testing. Even though testing sounds handy, making good test cases is in fact quite difficult, and bad tests can overlook bugs in the program. As an approach to completely ensure a certain property of a program, I introduce Coq, a tool in which we can write formal proofs and the validity of proofs is automatically checked. In the talk, I will begin with a short introduction on how to write programs and proofs in Coq, and then give some examples appearing in practical situations.
Friday, Oct. 20th, 2023 at 16:45-18:15
The URL of Zoom will be announced via the faculty’s mailing list 3 days before the colloquium.
The lecture material will be available in PandA at 16:15 on the day of the colloquium.
Dr. Akihito Suzuki
Network Resource Management Using Multi-Agent Deep Reinforcement Learning
The future evolution of networks will require various emerging communication technologies, such as Network Functions Virtualization (NFV) and Edge Computing (EC). NFV enables telecommunication providers to offer multiple network services by combining virtual network functions (VNFs). EC enhances computing capabilities at the network edges, enabling efficient task offloading. However, both technologies face challenges in optimizing resource allocation within the constraints of limited network and server resources. This presentation introduces network resource management methods using multi-agent deep reinforcement learning (MADRL) to rapidly find near-optimal resource allocations in future networks incorporating NFV and EC.
Friday, Nov. 17th, 2023 at 16:45-18:15
The URL of Zoom will be announced via faculty’s mailing list 3 days before the colloquium.
The lecture material will be available in PandA at 16:15 on the day of the colloquium.
Prof. Youngwoo Kim
Post Moore’s Law Era: Semiconductor Packaging Technology based System Scaling
Recently, transistor scaling represetned by Moore’s law is facing the limit. As a superior alternative, semiconductor packaing technology based system scaling has been proposed. 2.5/3 D integration based on packaging technology provies various benefis such as low-power consumption, small form-factor, and high system bandwidth. However, advanced packaing technology has also faced various limits such as extremely high design complexity, high-frequency noises, computational resource, and etc. In this talk, the definition of the packaing technology will be introduced with industrial difficulties. Also, various reaerches to solve the limit will be introdced considering signal/power integrity.
Friday, Dec. 15th, 2023 at 16:45-18:15
The URL of Zoom will be announced via the faculty’s mailing list 3 days before the colloquium.
The lecture material will be available in PandA at 16:15 on the day of the colloquium.
Prof. Yuto Nakashima
Dictionary compressors and repetitiveness measures
In lossless text compression, dictionary compressors are effective for highly repetitive texts, and many dictionary compressors have been proposed. For example, LZ77, the core of gzip, and grammar compression are well-known. However, a good model for capturing the string repetitiveness has yet to be known. Motivated by this fact, there is much research to theoretically understand string repetitiveness by discussing the relations between compression sizes (which we call repetitiveness measures) for each compressor. In this talk, I will introduce various dictionary compressors and recent research about repetitiveness measures.
Friday, Jan. 19th, 2024 at 16:45-18:15
The URL of Zoom will be announced via the faculty’s mailing list 3 days before the colloquium.
The lecture material will be available in PandA at 16:15 on the day of the colloquium.
Prof. Yu-Guang Chen
Navigating Aging Effects: Concepts and Implementation in Reliable Computing Systems
As CMOS technology undergoes further scaling down, the aging effect emerges as a non-negligible threat to the lifetime reliability of computing systems, potentially causing performance degradation or timing failures. Addressing these challenges requires a thorough understanding of how aging effects influence the results of modern computing systems, leading to the development of appropriate methodologies for aging detection, mitigation, and tolerance. In this presentation, I will provide a concise overview of major aging effects and their causes. I will then delve into two key aspects: (1) Aging-aware, energy-efficient task deployment for heterogeneous multicore systems, and (2) Aging-aware SRAM-based Computing-In-Memory architecture designed for multiply accumulate operations. Throughout, I will showcase innovative concepts proposed by our research team to tackle these challenges and discuss the implementation difficulties we’ve encountered. The aim is to furnish the audience with a foundational background in reliable computing system design and to inspire more researchers to contribute to this evolving field.