Proposed Protection Mechanism Research Articles

Exfoliated MoS2 with tunable size effect towards anticorrosion application

MoS2 sheets are becoming more and more active in the field of anticorrosion coatings. In this work, different size of MoS2 were fabricated by a simple gradient centrifugation approach then introduced into epoxy coatings (EP). Composite coatings with smaller size and larger size of MoS2 were also prepared for comparison. Anticorrosion properties of the coatings were evaluated via electrochemical spectroscopy, salt spray tests and theoretical calculation in detail. The impedance arc of doping the 1.4±0.1 μm of EM2000 for EP was 4.8×107 Ω cm2 after 7d immersing, which is much higher than that of EM800/EP, EM1000/EP and EM3000/EP. Salt spray test and corrosion products analysis have also proved the proposed protection mechanism of EM2000/EP coating. Doping the optimized size of EM2000 could form nano-network covering the microcracks to impede the diffusion of corrosive medium. In addition, the theoretical calculation showed that the body-center adsorption of O2 show the weaker physisorption with adsorption energies of ∼ −0.64 eV and −0.14 eV for H2O and O2. Excellent barrier ability and enhanced dispersion of the optimized size of MoS2 sheets were responsible for the superior enhancement of the anticorrosion performance of EP coating.

Exceptional Nuclease Resistance of DNA and RNA with the Addition of Small-Molecule Nucleobase Mimics.

Nucleases present a formidable barrier to the application of nucleic acids in biology, significantly reducing the lifetime of nucleic acid-based drugs. Here, we develop a novel methodology to protect DNA and RNA from nucleases by reconfiguring their supramolecular structure through the addition of a nucleobase mimic, cyanuric acid. In the presence of cyanuric acid, polyadenine strands assemble into triple helical fibers known as the polyA/CA motif. We report that this motif is exceptionally resistant to nucleases, with the constituent strands surviving for up to 1 month in the presence of serum. The conferred stability extends to adjacent non-polyA sequences, albeit with diminishing returns relative to their polyA sections due to hypothesized steric clashes. We introduce a strategy to regenerate stability through the introduction of free polyA strands or positively charged amino side chains, enhancing the stability of sequences of varied lengths. The proposed protection mechanism involves enzyme failure to recognize the unnatural polyA/CA motif, coupled with the motif's propensity to form long, bundling supramolecular fibers. The methodology provides a fundamentally new mechanism to protect nucleic acids from degradation using a supramolecular approach and increases lifetime in serum to days, weeks, or months.

Diverse Metrics for Robust LBS Privacy: Distance, Semantics, and Temporal Factors.

Addressing inherent limitations in distinguishing metrics relying solely on Euclidean distance, especially within the context of geo-indistinguishability (Geo-I) as a protection mechanism for location-based service (LBS) privacy, this paper introduces an innovative and comprehensive metric. Our proposed metric not only incorporates geographical information but also integrates semantic, temporal, and query data, serving as a powerful tool to foster semantic diversity, ensure high servifice similarity, and promote spatial dispersion. We extensively evaluate our technique by constructing a comprehensive metric for Dongcheng District, Beijing, using road network data obtained through the OSMNX package and semantic and temporal information acquired through Gaode Map. This holistic approach proves highly effective in mitigating adversarial attacks based on background knowledge. Compared with existing methods, our proposed protection mechanism showcases a minimum 50% reduction in service quality and an increase of at least 0.3 times in adversarial attack error using a real-world dataset from Geolife. The simulation results underscore the efficacy of our protection mechanism in significantly enhancing user privacy compared to existing methodologies in the LBS location privacy-protection framework. This adjustment more fully reflects the authors' preference while maintaining clarity about the role of Geo-I as a protection mechanism within the broader framework of LBS location privacy protection.

Protection against failure of machine-learning-based QoT prediction

Machine learning (ML)-based methods are being widely explored to predict the quality of transmission (QoT) of a lightpath. They are expected to reduce the signal-to-noise ratio margin reserved for the lightpath, thus improving the spectrum efficiency of an optical network. However, many studies on this prediction are often based on synthetic datasets or datasets obtained from laboratories. As such, these datasets may not accurately represent the entire state space of a practical optical network, which is exposed in harsh environments. There are risks of failure when using these ML-based QoT prediction models. Thus, it is necessary to develop a mechanism that can guarantee the reliability of lightpath service even if the prediction model fails. For this scenario, we propose to employ the conventional network protection techniques that are usually implemented to protect against network node/link failures to also protect against the failure of QoT prediction. Based on the two representative protection techniques, i.e., 1 + 1 dedicated path protection and shared backup path protection (SBPP), the performance of the proposed protection mechanism is evaluated by reserving different margins for the working and protection lightpaths. For 1 + 1 path protection, we find that the proposed mechanism can achieve a zero design margin (D-margin) for a working lightpath, thereby significantly improving network spectrum efficiency, while not sacrificing the availability of lightpath services. For SBPP, we find that an optimal D-margin should be identified to balance the spectrum efficiency and service availability; the proposed mechanism can save up to 0.5-dB D-margin for a working lightpath, while guaranteeing service availability.

Multipath Reliable Routing Using Cluster Based Communication

In this research we proposed the protection in ANT Optimized primarily based multipath congestion routing performance. Here the situation of DDoS is simulated and examines their impact in dynamic network. The multipath protocol like AOMDV is balance the all load by way of offering alternative path however not knowledgeable at each and every condition. The DDoS attacker is blocking off the whole viable direction in community by way of flooding large quantity of redundant packets in dynamic network. The attacker is that the intermediate node and this attacker contamination is continuously dispersing infection and the entire network overall performance is dumped. The proposed security scheme is identified attacker and their loss effect. Attacker is utterly disabled by way of proposed protection mechanism and their loss is also evaluated. The proposed approach is now not only detecting but also stop community from DDoS attack. The overall performance of protection scheme and assault is measured in three distinctive scenarios of a range of node densities. The proposed scheme is offers attacker free routing and get better network performance after making use of it. The performance of ANT OPTIMIZED is almost equal. The packets receiving, throughput, and PDR are bettering but the loss of packets and unnecessary flooding is decreased in dynamic network.

Modeling Attack Resistant PUFs Based on Adversarial Attack Against Machine Learning

The Physical Unclonable Function (PUF) has been proposed for the identification and authentication of devices and cryptographic key generation. A strong PUF provides an extremely large number of device-specific challenge-response pairs (CRP) which can be used for authentication. Unfortunately, the CRP mechanism is vulnerable to modeling attack, which uses machine learning (ML) algorithms to predict PUF responses. Many methods have been developed to strengthen strong PUFs; however, recent studies show that they are still vulnerable under refined ML algorithms with enhanced computing power. In this article, we propose to defend PUFs against modeling attacks from a different perspective. By modifying the CRP mechanism, a PUF can provide contradictory data such that an accurate prediction model of the PUF under attack cannot be built. Three different levels of threats are analyzed, and experimental results show that the proposed method provides an effective countermeasure against ML based modeling attacks. The proposed protection mechanism is validated using FPGA, and the results show that the performance of PUFs is also improved with the help of the proposed protection mechanism. In addition, the proposed method is compatible with hardware strengthening schemes to provide even better protection for PUFs.

Framework for Slice-Aware Radio Resource Management Utilizing Artificial Neural Networks

For accommodating the heterogeneous services that are anticipated for the fifth-generation (5G) mobile networks, the concept of network slicing serves as a key technology. Spanning both the core network (CN) and radio access network (RAN), slices are end-to-end virtual networks that share the resources of a physical network. Slicing the RAN can be more challenging than slicing the CN since RAN slicing deals with the distribution of radio resources, which have fluctuating capacity and are harder to extend. Improving multiplexing gains, while assuring the slice isolation is the main challenging task for RAN slicing. This paper provides a flexible and configurable framework for RAN slicing, where diverse requirements of slices are simultaneously taken into account, and slice management algorithms adjust the control parameters of different radio resource management (RRM) mechanisms to satisfy the slices’ service level agreements (SLAs). One of the proposed algorithms is based merely on heuristics and the other one utilizes an artificial neural network (ANN) to predict the behavior of the cellular network and make better decisions in the adjustment of the RRM mechanisms. Furthermore, a protection mechanism is devised to prevent the slices from negatively influencing each other’s performances. A simulation-based analysis demonstrates that in presence of local or global overload of one of the slices, the ANN-based method increases the number of key performance indicators (KPIs) that fulfill their defined SLA targets. Finally, we show that the proposed protection mechanism can force the negative effects of an overloading slice to be contained to that slice and the other slices are not affected as severely.

A Reopened Crowbar Protection for Increasing the Resiliency of the Vacuum Tube High-Voltage DC Power Supply Against the Vacuum Arc

High-voltage power supplies (HVPSs) are widely used to supply vacuum tubes. The amount of delivered energy from the HVPS to the tube is an important issue during the vacuum arc in the tube. The conventional protection mechanism consists of a shunt crowbar which diverts the fault current from the tube to itself as a parallel path. The crowbar circuit is usually built of the devices without the turn-off capability. It is a drawback since the output of the power supply is shortened for a long time. Thus, the restoration time of these power supplies is excessive. This demerit can have detrimental effects on mission-critical applications. In this paper, the insulated-gate bipolar transistor (IGBT)-based crowbar structure is studied to overcome this issue. In the proposed protection mechanism, the crowbar can be reopened intentionally after closing. A theoretical analysis is presented to compare power supply performance in the presence of the conventional crowbar with the IGBT-based crowbar. The experimental results are presented to demonstrate the practical considerations of the proposed crowbar structure and its appropriate performance. This paper shows that HVPS has more fault resiliency and less restoration time with the proposed IGBT-based crowbar.

A binary‐regularization‐based model predictive control applied to generation scheduling in concentrating solar power plants

SummaryThis paper proposes the use of model predictive control (MPC) with binary‐regularization to manage the electric power generation problem in concentrating solar power plants with thermal energy storage. The main advantage of the of MPC with binary‐regularization formulation is the inclusion of a power block protection method based on a binary‐regularization term that penalizes power generation variation (also called generation cycling) differently according to the power block situation, ie, normal operation, startup, or shutdown. This distinction simplifies the choice of schedules with reduced variation and high energy sale profits. The interest in this reduction is the achievement of a higher lifetime of the power block elements, lower maintenance costs, and easier plant operability. A benefit of the generation scheduling based on MPC is the capacity of rescheduling the power generation at regular periods, taking advantage of the most recent energy prices and weather forecast, and of the plant's current state. An interesting question is if the proposed protection mechanism affects the economic results of the MPC black strategy. In this regard, an economic study based on a realistic simulation of a 50 MW parabolic trough collector‐based concentrating solar power plant with thermal energy storage, under the assumption of participation in the Spanish day‐ahead energy market scenario, is included. Realistic values for actual and forecasted solar resource and for energy price are used, and for penalties for deviation from the committed generation schedule. The economic study shows that the proposed scheduling method provides an important reduction of the generation cycling without decreasing energy sales profits. Another advantage of the proposed method is the possibility of estimating the highest level of power block protection, which maintains the profits by means of historical data, which favors its practical implementation.

Surface-decorated silica with Schiff base as an anticorrosive coating for aluminium alloy 2024-T3

Schiff base orthosilicate 7 was synthesised and its inhibitory properties against corrosion when deposited on the 2024-T3 aluminium alloy in 0.05 mol·L−1 NaCl were investigated by electrochemical impedance spectroscopy, potentiodynamic polarisation and scanning electron microscopy technique. Polarisation curves indicated that the orthosilicate 7 studied acts by decreasing the anodic and cathodic activity on the alloy surface, and presents effective barrier properties as an anticorrosive conversion layer, retarding the corrosion and pitting potentials of alloy. The electroactivity of Schiff base orthosilicate 7 was attributed to the presence of nitrogen and oxygen atoms and the flexible spacer group which showed better adsorption properties on metallic surfaces by forming complexes between 7 and metals. Specific potentials can produce different Schiff base orthosilicate 7 complexes on the metal surface according to the reduction wave at around −1.1 V on platinum, and −0.27 V on AA2024-T3 (vs. the platinum pseudoreference microelectrode). The proposed protection mechanism is based on the adsorption of the silicate portion on the matrix phase of the alloy, by metaloxosilane bonds (AlOSi), and by complexed structures in the flexible group chain of the Schiff base portion on intermetallics enriched by copper (N----Cu+2 and O----Cu+2).

Balanced Power Amplifier Protection Against Load Mismatch

This letter presents a new approach for balanced power amplifier protection against load mismatch under pulsed-RF operation. The proposed protection mechanism completely eliminates the reflected power under severe mismatch conditions while not affecting nominal operating condition. The concept is based on detection, comparison, and switching technique. The proposed protection circuit offers full protection against open and short at the output. This protection mechanism has been demonstrated on a 10-W $X$ -band power amplifier, intended to be used in space borne radar payloads. The reaction time of the proposed protection mechanism is <100 ns.

Efficient and Reliable Protection Mechanism in Long-Reach PON

Network survivability and protection mechanisms are very important and necessary in optical networks. The long-reach passive optical network (LR-PON) proposed in this paper extends the access network to hundreds of kilometers, and it can support more optical network units by wavelength division multiplexing technology. We propose an efficient protection mechanism for the whole LR-PON. Optical encoders are used to monitor the whole network, and a network management system in the central office will initialize the protection process by monitoring the information it collects. When the network works normally, space division multiplexing technology is adopted to reduce the loss and crosstalk of signals. The designed system propagates the upstream and downstream signals in different fiber rings to mitigate the influence of Rayleigh backscattering. The proposed protection mechanism can protect the network from the multi-faults of fiber links with the designed switches. Furthermore, the loss, availability, costs, and network performance are also studied. The results obtained prove the feasibility of the proposed network. The network is costless and reliable, and it has high availability of up to 99.9992% by the protection mechanism.

Simulation of protection mechanisms against infrastructure attacks based on the “nervous network system” approach

The paper considers an analysis of a protection mechanism against infrastructure attacks based on the bio-inspired approach ―nervous network system‖. We propose to use a network packet-level simulation to investigate the protection mechanism ―nervous network system‖. The paper presents the structure of the protection mechanism, the algorithms of its functioning, and the results of the experiments. Basing on the experimental data, we analyze the effectiveness of the proposed protection mechanism.

A Shoot-Through Protection Scheme for Converters Built With SiC JFETs

The SiC JFET is an attractive semiconductor device due to its superior switching performance and high-temperature operating capability. Its shoot-through protection remains a challenge due to the limited practical knowledge existent on this device and due to its inherent normally on nature. Addressing this limitation, this paper presents a novel shoot-through protection scheme in which a bidirectional switch, compounded by a Si insulated-gate bipolar transistor (IGBT) and a relay,is embedded into the dc-link midpoint in order to detect and clear shoot-through faults, taking advantage of the well-known desaturation protection schemes of IGBTs to protect SiC JFETs. This paper describes in detail the proposed protection mechanism and its circuit design, presenting as well the experimental results that verified the effectiveness of the proposed scheme using, first, Si MOSFETs and second, a 10-kW ac–ac converter system using SiC JFETs.

Thiotaurine and hypotaurine contents in hydrothermal‐vent polychaetes without thiotrophic endosymbionts: correlation With sulfide exposure

Invertebrates at hydrothermal vents and cold seeps must cope with toxic H(2)S. One proposed protection mechanism involves taurine derivatives: At vents and seeps, many animals have high levels of hypotaurine and thiotaurine (a product of hypotaurine and HS), originally found in animals with thiotrophic endosymbionts. To further test the role of these compounds, we analyzed them in vent polychaetes without endosymbionts: Paralvinella sulfincola, P. palmiformis and P. pandorae (paralvinellids) and Nicomache venticola (maldanid). P. sulfincola were collected from a high temperature (42-68 degrees C) and a warm site (21-35 degrees C). P. palmiformis and pandorae were from cool sites (12-18 degrees C) and N. venticola were from a cold site (4 degrees C). H(2)S concentrations in vent effluent largely correlate with temperature. Some specimens were frozen; other ones were kept alive in laboratory chambers, with and without sulfide. Tissues were analyzed for taurine derivatives and other solutes that serve as organic osmolytes. The major osmolyte of all species was glycine. Thiotaurine contents were significantly different among all species, in the order P. sulfincola hot>P. sulfincola warm>P. pandorae>P. palmiformis>N. venticola. P. sulfincola also had high levels of sarcosine; others species had none. Sarcosine and hypotaurine contents of P. sulfincola's branchiae were higher, while glycine contents were lower, than in main body. In P. palmiformis kept in pressure chambers with sulfide, thiotaurine contents were higher and hypotaurine lower than in those kept without sulfide. These results support the hypothesis that conversion of hypotaurine to thiotaurine detoxifies sulfide in vent animals without endosymbionts.

Protection switching and local area network emulation in passive optical networks

This paper proposes and experimentally demonstrates an automatic-protection-switching (APS) mechanism against distribution fiber breaks in passive optical networks (PONs). The protection of optical-network units (ONUs) that are located at the customer premises is carried out by monitoring the distribution fiber using the traffic that is transported among the customers in the PON. This configuration emulates a local area network (LAN) over the existing PON while facilitating the switching of signal transmissions to a predetermined protection path in an event of a distribution fiber break. As failure detection and APS are performed independently by each ONU in a distributed manner, the processing complexities and delays are reduced at the central office (CO). The restoration of the traffic transported between the CO and an ONU in the event of the distribution fiber break is performed by interconnecting adjacent ONUs and carrying out signal transmissions via an independent but interconnected ONU. Such a protection mechanism enables multiple adjacent ONUs to be simultaneously protected by a single ONU utilizing its maximum available bandwidth. This paper experimentally verifies the feasibility of the proposed protection mechanism in conjunction with two different LAN-emulation schemes with a 1.25-Gb/s upstream baseband transmission to the CO and a 155-Mb/s LAN data transmission on a radio-frequency carrier. The experimental results obtained from both schemes are compared, and the power budgets are calculated to analyze the scalability of each scheme.

Aluminum ion mediated stabilization of silica-based anion-exchange packings to caustic regenerants

Silica-based chromatography columns can be effectively regenerated with sodium hydroxide solutions containing millimolar levels of aluminum salts. The presence of aluminum ions in the caustic wash significantly reduced and in some cases virtually eliminated silica dissolution from silica-based anion-exchange columns. Wide-pore polymer coated anion-exchange packings for protein separations were washed in excess of 100 cycles with 0.1 M and 0.5 M sodium hydroxide containing aluminum nitrate with no detectable deterioration of the column bed or chromatographic performance. The protection results from incorporation of aluminosilicate sites on the silica support surface beneath the polymeric coating. This aluminosilicates is insoluble in the operational pH range (5–9), therefore aluminum (as Al 2O 3) is undetectable at a sensitivity of 800 parts per 10 9 in the chromatographic effluent. The protective aluminosilicate can be removed by an acid wash. The physical/chemical changes in the column packing which result from caustic washing were studied by solid-state NMR and other physical techniques. The extent of modification, proposed protection mechanism and the influence on chromatographic performance are discussed.