801 research outputs found
sj-docx-1-ras-10.1177_00208523211043362 - Supplemental material for The effects of performance evaluation on punishment in organisations
No full textSupplemental material, sj-docx-1-ras-10.1177_00208523211043362 for The effects of performance evaluation on punishment in organisations by Seungwon Yu, Eun Ji Yoo and Suhee Kim in International Review of Administrative Sciences</p
Isotopies of surfaces in 4–manifolds via banded unlink diagrams
No full text© 2020, Mathematical Sciences Publishers. We study surfaces embedded in 4–manifolds. We give a complete set of moves relating banded unlink diagrams of isotopic surfaces in an arbitrary 4–manifold. This extends work of Swenton and Kearton–Kurlin in S4. As an application, we show that bridge trisections of isotopic surfaces in a trisected 4–manifold are related by a sequence of perturbations and deperturbations, affirmatively proving a conjecture of Meier and Zupan. We also exhibit several isotopies of unit surfaces in CP2 (ie spheres in the generating homology class), proving that many explicit unit surfaces are isotopic to the standard CP1. This strengthens some previously known results about the Gluck twist in S4, related to Kirby problem 4.2311Nsciescopu
Enhancing Interphase Stability Through π–π Interactions of Fluorinated Aromatic Additives with Hard Carbon Electrodes in Sodium-Ion Batteries
No full textEnhancing Interphase Stability Through π–π Interactions of Fluorinated Aromatic Additives with Hard Carbon Electrodes in Sodium-Ion Batterie
RE-CHECKER: Towards Secure RESTful Service in Software-Defined Networking
No full textOver the years, Software-Defined Networking (SDN) has grown aggressively, and many SDN controller products have been released to date as not only open source projects but also commercial ones. Considering the adoption of SDN, the security of SDN components is an essential aspect that needs to be thoroughly investigated, so research in this area has been getting attention. However, despite growing interest in SDN security, SDN controllers are vulnerable to security vulnerabilities that have not yet been disclosed. Among them, we focus on RESTful services provided by SDN controllers because those services help users to implement useful network functions in a programmable way, so it can be a critical attack point to an adversary. Therefore, in this work, we try to find out vulnerabilities and bugs of the RESTful service implementation, which are powerful enough to jeopardize the entire network. To more efficiently detect those vulnerabilities and bugs, we introduce a framework called RE-CHECKER that can find the security holes of RESTful services in SDN controller. As a result, using RE-CHECKER, we found four bug types against three open source controllers: ONOS, Floodlight, and Ryu. To prove the feasibility and examine the potential impact of each vulnerability and bug, we demonstrate some vulnerable scenarios in the real SDN environments
Knowledge Seeking on The Shadow Brokers
No full textThe Shadow Brokers (TSB) are an infamous group of hackers responsible for major cybercrime incidents. There are currently few studies on TSB, and to prevent their attacks in the future, we believe it is necessary to study them beforehand. This study constructs a relation graph of all the entities concerning TSB using identifiers in the Web. We introduce a systematic approach to finding relations among entities using a case study based on identifiers and clearness of relations. Our investigation covers data from both the Surface Web and Dark Web, with our Dark Web data consisting of over 40 million Dark Web webpages. We have uncovered many hacking forums, hacking groups, and individuals having a relation with TSB using our method. The relation graph of TSB will become a stepping stone in developing a knowledge base of TSB
Cryonics: Trustworthy Function-as-a-Service using Snapshot-based Enclaves
No full textRecent research has proposed the use of trusted execution environments (TEEs), such as SGX, in serverless computing to safeguard against threats from insecure system software, malicious co-located tenants, or suspicious cloud operators. However, integrating SGX, one of the most mature TEE, with serverless computing results in significant performance degradation due to the function startup latency caused by enclave creation. This performance degradation arises because SGX is not designed with serverless function startup procedures in mind, where numerous application codes, libraries, and data are re-initialized upon each function invocation. The inherent limitations of SGX contribute to significant performance degradation, whether through the addition of every page into the enclave, or the restriction of page permissions, which ultimately cause TLB flushes, context switches, and re-entering the enclave. In this paper, we first take key observations resident in the intrinsic features of the server-less function and propose Cryonics, a method of serving snapshot-based enclave that accelerates the startup time of the function instance by creating a future-proof working set of that. We consider the page locality and obsolete pages of the enclaved function instance to create a lightweight working set used for serving requests. Our evaluation shows that Cryonics achieves up to 100x outperformed startup time compared to existing cold-start-based methods and reveals the stability of the startup time
sj-docx-1-tag-10.1177_17562848231189957 – Supplemental material for Comparison of high-flow nasal cannula and conventional nasal cannula during sedation for endoscopic submucosal dissection: a retrospective study
No full textSupplemental material, sj-docx-1-tag-10.1177_17562848231189957 for Comparison of high-flow nasal cannula and conventional nasal cannula during sedation for endoscopic submucosal dissection: a retrospective study by Seungwon Lee, Ji Won Choi, In Sun Chung, Duk Kyung Kim, Woo Seog Sim and Tae Jun Kim in Therapeutic Advances in Gastroenterology</p
AVX-TSCHA: Leaking information through AVX extensions in commercial processors
No full textModern x86 processors support an AVX instruction set to boost performance. However, this extension set may also cause security issues. We discovered that there are vulnerable properties in the implementation of the masked load/store instructions. First, these instructions can suppress exceptions caused by invalid or inaccessible memory access. Second, the execution time of these instructions leaks the current state of the page mappings, permissions, and TLB states. Based on this, we present a novel AVX timing side-channel attack that can defeat address space layout randomization. We demonstrate the significance of our side-channel attack by showing User and Kernel ASLR breaks on the recent Intel and AMD processors in various environments, including cloud computing systems (Amazon AWS, Google GCP, and Microsoft Azure), an SGX enclave (a fine-grained ASLR break), and major OSes (Linux, Windows, and macOS). Our attack can identify the Linux kernel's base address in 0.29 ms as well as those of loaded kernel modules in 2.24 ms, with a near-zero error rate. We further demonstrate that our attack can be used to infer user behavior, such as mouse movements and data transmissions over the network. Our evaluation results on multiple mobile, desktop, and server processors (a total of 26 Intel and AMD CPUs) show that 1) the AVX timing side-channel works on the vast majority of Intel processors (from the Sandy Bridge microarchitecture) as well as AMD processors (from the Zen microarchitecture onward) and 2) our KASLR breaks are very fast and reliable. To the best of our knowledge, our attack is the first to demonstrate a KASLR break on both the recent Intel Alder Lake and AMD Zen 3 CPUs. We highlight that more robust isolation or fine-grained randomization should be adopted to mitigate our presented attacks successfully.
A New Enhanced Coding Scheme for Robust Bit-stream of ATSC DTV
No full textIn this paper a new enhanced coding scheme of ATSC DTV standard is presented. The proposed coding scheme is a modified trellis codes of enhanced 8-VSB for robust bitstream mode. By computing the distance spectrum, we derive the theoretical upper bound on the first event error probability of the proposed trellis codes. Based on the derivation, the proposed coding scheme has slightly better performance on AWGN channel than the conventional enhanced 8-VSB coding scheme at high signal-to-noise ratio (SNR). We also show that the proposed coding scheme has better performance than any existing coding schemes of ATSC DTV standard by using the Monte Carlo simulations
MiniCon: Automatic Enforcement of a Minimal Capability Set for Security-Enhanced Containers
No full textNowadays, containers have been widely adopted not only for clouds but also for individual users. On the one hand, containers provide much more light-weight virtualized infrastructure, but on the other hand, it is unavoidable to handle security issues since the isolation of containers is relatively weak, compared to the legacy VMs. Under the container architecture, adversaries are able to exploit kernel vulnerabilities to escalate privilege to gain root privilege, and leak system, privacy critical information. Although previous solutions provide strong security protection, unfortunately, none of them do provide a way to apply policies. Therefore, in this paper, we present an eBPF-based capability enforcement system, MiniCon, that automatically generates and enforces a minimal capability set by using Seccomp Filter. It monitors capability requests from containers, merges those requests to create a minimal capability set, and enforces capability policies through Seccomp Filter
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