Type II Anyon Superconductivity

Assuming that the superconductivity which is described by the low energy effective action of the anyon system may be type II, we discuss its characteristics. We also study physical properties of the Chern-Simons vortices, which may be formed as the external magnetic field is applied to the system, such as their statistics, the free energy of single vortex and the interaction energy between two vortices.Comment: 12 pages, REVTEX, no figure

Topological Ward Identity and Anti-de Sitter Space/CFT Correspondence

The dual relationship between the supergravity in the anti-de Sitter(AdS) space and the superconformal field theory is discussed in the simplest form. We show that a topological Ward identity holds in the three dimensional Chern-Simons gravity. In this simple case the proposed dual relationship can be understood as the topological Ward identity. Extensions to the supersymmetric theories and higher dimensional ones are also briefly discussed.Comment: 11 Pages, Revte

Body and Politic in Modern Japan:

Organicism has long been considered as a subcategory of social Darwinism. However, acknowledging that organicism is intimately connected with social Darwinism does not mean that there is any necessary connection between organicism and authoritarian or totalitarian discourse. These misunderstandings are mainly based on the belief that organicism cannot be compatible with individualism. This alleged incompatibility, however, rests on the confusion between various viewpoints of the body. Cell theory, on which Herbert Spencers thought is based, can illustrate that independent units constitute the body in cooperation with other units without the centralization of control and the subjugation of the parts to the interests of the whole. In this view, the reception of the meaning of organism in Japan also cannot be irrelevant to the conception of the body in Japan. Consequently, organism and its Japanese translation yūkitai cannot have the same meaning and usage. When Spencers social organism was translated in modern Japan, the Japanese translator agreed with Spencer that the same logic exists between the biological and social body. Nonetheless, Spencers organicism, rather than his individualism, was appropriated to support the introduction of the parliamentary system. What Japanese politicians wanted to see through Spencers organicism was the urgent need to introduce the representative system in Japan. However, strictly speaking, this is not the gist of Spencers cell-oriented organicism. Decoupling the political thought from biology in Meiji Japan, where the meaning of cell theory was not accepted, brings out this discrepancy

pFedDef: Defending Grey-Box Attacks for Personalized Federated Learning

Personalized federated learning allows for clients in a distributed system to train a neural network tailored to their unique local data while leveraging information at other clients. However, clients' models are vulnerable to attacks during both the training and testing phases. In this paper we address the issue of adversarial clients crafting evasion attacks at test time to deceive other clients. For example, adversaries may aim to deceive spam filters and recommendation systems trained with personalized federated learning for monetary gain. The adversarial clients have varying degrees of personalization based on the method of distributed learning, leading to a "grey-box" situation. We are the first to characterize the transferability of such internal evasion attacks for different learning methods and analyze the trade-off between model accuracy and robustness depending on the degree of personalization and similarities in client data. We introduce a defense mechanism, pFedDef, that performs personalized federated adversarial training while respecting resource limitations at clients that inhibit adversarial training. Overall, pFedDef increases relative grey-box adversarial robustness by 62% compared to federated adversarial training and performs well even under limited system resources.Comment: 16 pages, 5 figures (11 images if counting sub-figures separately), longer version of paper submitted to CrossFL 2022 poster workshop, code available at (https://github.com/tj-kim/pFedDef_v1

Communication during the Pandemic: Use of videoconferencing in Audit Committee-Auditor Communication

Using Korean listed firms’ mandatory disclosure on the communication method for meetings between the Audit Committee and auditors from 2019 to 2020, we find that videoconferencing leads to weaker audit quality. We measure the degree of videoconferencing by the proportion of videoconferencing in the total number of meetings between the Audit Committee and auditors. We provide preliminary results on whether changes in communication methods affect audit quality. Our results are robust to change analyses, balanced sample analyses, including auditor fixed effects, and using an alternative measure of audit quality and videoconferencing. We find that Audit Committee independence or expertise does not affect the relationship between videoconferencing and audit quality but holding more formal Audit Committee meetings during the year mitigates the negative impact of videoconferencing on audit quality. Our paper contributes to the literature on information processing of Audit Committees

クリーンな採水と分析法を用いた海水中の極微量亜鉛の濃度と存在状態に関する研究

学位の種別: 課程博士審査委員会委員 : (主査)東京大学教授 蒲生 俊敬, 東京大学教授 植松 光夫, 東京大学教授 長尾 敬介, 東京大学教授 松尾 基之, 東京大学教授 中井 俊一University of Tokyo(東京大学

Adversarial Robustness Unhardening via Backdoor Attacks in Federated Learning

In today's data-driven landscape, the delicate equilibrium between safeguarding user privacy and unleashing data potential stands as a paramount concern. Federated learning, which enables collaborative model training without necessitating data sharing, has emerged as a privacy-centric solution. This decentralized approach brings forth security challenges, notably poisoning and backdoor attacks where malicious entities inject corrupted data. Our research, initially spurred by test-time evasion attacks, investigates the intersection of adversarial training and backdoor attacks within federated learning, introducing Adversarial Robustness Unhardening (ARU). ARU is employed by a subset of adversaries to intentionally undermine model robustness during decentralized training, rendering models susceptible to a broader range of evasion attacks. We present extensive empirical experiments evaluating ARU's impact on adversarial training and existing robust aggregation defenses against poisoning and backdoor attacks. Our findings inform strategies for enhancing ARU to counter current defensive measures and highlight the limitations of existing defenses, offering insights into bolstering defenses against ARU.Comment: 8 pages, 6 main pages of text, 4 figures, 2 tables. Made for a Neurips workshop on backdoor attack

Prediction of a time-to-event trait using genome wide SNP data

BACKGROUND: A popular objective of many high-throughput genome projects is to discover various genomic markers associated with traits and develop statistical models to predict traits of future patients based on marker values. RESULTS: In this paper, we present a prediction method for time-to-event traits using genome-wide single-nucleotide polymorphisms (SNPs). We also propose a MaxTest associating between a time-to-event trait and a SNP accounting for its possible genetic models. The proposed MaxTest can help screen out nonprognostic SNPs and identify genetic models of prognostic SNPs. The performance of the proposed method is evaluated through simulations. CONCLUSIONS: In conjunction with the MaxTest, the proposed method provides more parsimonious prediction models but includes more prognostic SNPs than some naive prediction methods. The proposed method is demonstrated with real GWAS data