A graph is NIC-planar if it admits a drawing in the plane with at most one crossing per edge and such that two pairs of crossing edges share at most one common end vertex. NIC-planarity generalizes ...IC-planarity, which allows a vertex to be incident to at most one crossing edge, and specializes 1-planarity, which only requires at most one crossing per edge.
We characterize embeddings of maximal NIC-planar graphs in terms of generalized planar dual graphs. The characterization is used to derive tight bounds on the density of maximal NIC-planar graphs which ranges between 3.2(n−2) and 3.6(n−2). Further, we prove that optimal NIC-planar graphs with 3.6(n−2) edges have a unique embedding and can be recognized in linear time, whereas the general recognition problem of NIC-planar graphs is NP-complete. In addition, we show that there are NIC-planar graphs that do not admit right angle crossing drawings, which distinguishes NIC-planar from IC-planar graphs.
Generally, the synthesis of precursors for metal oxide anode and LiNiO2-based cathode materials undergoes different routes. Herein, NiO anode and LiNiO2 cathode material for lithium-ion batteries are ...synthesized by sharing the rod-like NiC2O4 precursor which is prepared by the solvothermal method. As a result, NiO and LiNiO2 exhibit special fibrous structure and promising electrchemical performances without any modification. Especially, the synthesis of fibrous LiNiO2 via a solvothermal route and its electrochemical properties are first reported. The excellent electrochemical performances of LiNiO2 can be attributed to the decent fiber architecture which enhances wettability by the electrolyte and shortens Li+ diffusion pathways.
Display omitted
In this article, we present a physically oriented design of broadband RF negative non-Foster capacitors. The design procedure is based on the matrix decomposition of Linvill's floating negative ...impedance converter (NIC). The decomposition allows optimization of the NIC circuit regarding the accuracy of generated capacitance. Furthermore, it provides a clear physical picture of the influence of particular circuit elements on the system properties. The methodology is verified by the design and measurements of a negative capacitor in a 0.5-2 GHz range, suitable for applications in bandpass filters with the NIC-based impedance inverters. Experimental results were found to be in good agreement with the theoretical predictions, verifying the correctness of the presented approach.
A Survey of Storage Systems in the RDMA Era Ma, Shaonan; Ma, Teng; Chen, Kang ...
IEEE transactions on parallel and distributed systems,
2022-Dec.-1, 2022-12-1, Letnik:
33, Številka:
12
Journal Article
Recenzirano
Remote Direct Memory Access (RDMA) based network devices are increasingly being deployed in modern data centers. RDMA brings significant performance improvements over traditional network devices such ...as Ethernet due to its unique features: protocol offloading and memory semantics . In particular, it can achieve microsecond level latency, which is about 2<inline-formula><tex-math notation="LaTeX">\sim</tex-math> <mml:math><mml:mo>∼</mml:mo></mml:math><inline-graphic xlink:href="ma-ieq1-3188656.gif"/> </inline-formula>3 orders of magnitude improvement. With such improvement in hardware, the software stack, including device drivers and programming libraries, is becoming a new performance bottleneck. Developers need to use new programming libraries to take full advantage of the performance of the underlying hardware. Storage systems are very important in modern data centers. This article surveys the current efforts to use RDMA for optimizing storage systems. We first present five classes of RDMA-based storage systems, including key-value stores, file systems, distributed memory systems, database systems, and systems using smart NICs, to demonstrate different design choices. Then, we examine the core modules of storage systems from different perspectives: communication mode, concurrency control, fault tolerance, caching, and resource management. Finally, we provide some design guidelines for new RDMA-based storage systems, as well as a discussion of opportunities and challenges.
This work delves into the vital role of TLS (Transport Layer Security) in securing web applications today. We explore kTLS (Kernel TLS) offloading as a possible solution to alleviate resource strain ...such as CPU time, power consumption, and network speed. By shifting cryptographic tasks closer to the CPU in software offloading or away from the main CPU in hardware offloading, kTLS can improve resource efficiency. Our experimental studies assess various offloading strategies, including software-based kTLS that bring it closer to the Kernel and cutting-edge hardware-accelerated modes such as TOE and coprocessor configurations using the Chelsio T6 SmartNIC. We highlight the immense potential of kTLS and network adapters in reshaping performance and efficiency dynamics for some network environments, considering each approach's benefits and potential drawbacks.
This paper dissertates about the influence of space weather event from September 2017 on parameters NAC and NIC in ADS-B messages. Space weather have potential to influence GNSS navigation. ...Especially in the aviation, where we depend on th GNSS more. Therefore we examined the influence of solar flares on the aviation navigation system of commercial aircraft. We used data broadcasted by ADS-B system during the most severe space weather event. Parameters NAC and NIC describe the level of reliability of the aircraft position information based on the GNSS. Therefore, they might be partially used as sensors of any irregularities in GNSS signal. We focus on these parameters during one of the most severe solar flare in recent years to establish if there is any observable influence of the space weather on these parameters. We were able to prove that even during this severe flare that there was no degradation in the availability of the GNSS.
The in vitro susceptibility to sodium metabisulphite (NaMBS) was investigated in 10 different food spoilage filamentous fungi, namely Aspergillus flavus, A. carbonarius, A. niger, A. ochraceus, A. ...tubingensis, A. westerdijkiae, Cladosporium cladosporioides, Fusarium oxysporum, Penicillium commune and P. expansum. The fungi were inoculated in sterile 96-well microtiter plates containing Yeast-extract Sucrose (YES) semi-solid agar supplemented with NaMBS in concentrations ranging from 2000 to 3.9 mg l−1 and incubated at 25 °C. Growth was monitored by absorbance measurements at 600 nm using a multi-spectrophotometer. The surface areas under the optical density (OD) vs. time growth curves obtained were used to calculate the fractional area f(a), from which the non-inhibitory (NIC) and minimum inhibitory concentrations (MIC) of the antifungal agent were calculated for each fungus using the Gompertz model for decay. Most Aspergillus species showed remarkable resistance to NaMBS, presenting NIC and MIC values higher than 250 and 2500 mg l−1, respectively. The most susceptible fungi were the two Penicillium species and A. carbonarius, which presented very low NIC (<100 mg l−1) and MIC (<1300 mg l−1) values, whereas C. cladosporioides and F. oxysporum presented intermediate values. The method has the advantage of good repeatability and accuracy, rapid results within 48–72 h, growth detection and susceptibility to the antifungal agent for several fungi at the same time, and optimal use of microbiological media by using small volumes of consumables.
Display omitted
•Fast determination of inhibition concentrations of sodium metabisulphite for different food spoilage fungi•A. carbonarius and Penicillium spp. found to be the more sensitive among fungi tested.•A. flavus and A. tubingensis were the least susceptible species to sodium metabisulphite.
This study presents a specific case of how a teacher in China learned to teach with problem posing through a collaborative, iterative design process with a researcher. Supported by a networked ...improvement community, at every step of the journey that they undertook, they partnered to design, deliver, and revise a mathematics lesson that fostered students’ learning through problem posing. A detailed travelogue of their journey serves to document what research on teaching through mathematical problem posing can look like and how the teacher learned to teach using this novel approach. We explore the utility of the 3H (head, heart, and hands) model as a powerful way to think about holistic, transformative teacher learning. In addition, we consider aspects of the networked improvement community in which the teacher–researcher partnership operated that enabled capacity for sustaining this kind of effort to change practice.
•This study follows a journey of a teacher and a researcher designing, delivering, and revising a problem-posing-based lesson.•Shows how research on teaching through mathematical problem posing can look when conducted by a teacher–researcher partnership in an NIC.•Discusses utility of the 3H (head, heart, and hands) model as a holistic tool to describe teachers' transformative learning.
PDF
