Security in Network Virtualization: A Survey Jee, Seung Hun; Park, Ji Su; Shon, Jin Gon
Journal of information processing systems,
08/2021, Letnik:
17, Številka:
4
Journal Article
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Network virtualization technologies have played efficient roles in deploying cloud, Internet of Things (IoT), big data, and 5G network. We have conducted a survey on network virtualization ...technologies, such as software-defined networking (SDN), network functions virtualization (NFV), and network virtualization overlay (NVO). For each of technologies, we have explained the comprehensive architectures, applied technologies, and the advantages and disadvantages. Furthermore, this paper has provided a summarized view of the latest research works on challenges and solutions of security issues mainly focused on DDoS attack and encryption.
In Lithuania the NGO sector is currently undergoing dramatic changes, alongside the public and private sectors. Its complexity is apparent not only in its relative growth and intrinsic significance, ...but also in its possibilities for integration into the other sectors. This complexity produces difficulties in understanding and defining third-sector organisations. This article addresses the issue of the compatibility of the social and economic aspects of Lithuanian NGOs with sustainable development. The relation between NGOs and the market is not clearly defined; for instance, it is often said that voluntary NGOs cannot compete with the service sector in terms of incomes. Such notions make an understanding of the role and place of NGOs between public and private sectors even more remote. Qualitative research shows that the concept of the NGO is unclear not only to the public but also to government and business. If the participation of NGOs in the market is becoming problematic, it is because their origin, nature and activities are very complex. Over half of all NGO founders already knew, at the time of inception, that the social programmes or missions of the organisations they had created would involve economic activity. While NGO leaders declare that such activity is necessary for survival, a necessary supplement to the main work of their organisations, informants agree that the sale of services should never become the main impetus of NGOs, since this would risk their ability to question existing social structures, to pose solutions to pressing social problems, and to enter into partnerships with society, the market and the state.
Šiuolaikinės Lietuvos visuomenės rinkos, valdžios ir NVO arba pilietinės visuomenės sektoriai bei jų tarpusavio sąveika nuolat patiria įvairius pokyčius. Ypač neapibrėžta ir sudėtinga yra NVO sektoriaus plėtra bei jo santykis su kitais dviem sektoriais. Įvairi ir daugialypė NVO prigimtis bei šio sektoriaus organizacinės struktūros ir fukcionavimo kaita trukdo suprasti ir vienareikšmiškai apibrėžti NVO sektorių. Juo labiau, kad ilgą laiką dominavo nuostata, kad NVO sektoriui yra svetima ekonominė veikla, kad ją gali organizuoti ir koordinuoti tik valdžios ir rinkos sektoriai. Šio straipsnio tikslas – išanalizuoti Lietuvos psichosocialines paslaugas teikiančių NVO1 (toliau – NVO) socialinio ir ekonominio matmens tarpusavio santykį darnios plėtros požiūriu. Lietuvoje NVO ir rinkos santykis iki šiol yra labai miglotas ir aiškiai neapibrėžtas, kadangi dominuoja nuomonė, kad NVO ir už įvairias prekes/paslaugos gaunamos pajamos nėra suderinami dalykai. Šis aiškios NVO sampratos nebuvimas neleidžia pačioms ne pelno siekiančioms NVO suvokti savo vietą tarp valdžios institucijų ir rinkos dalyvių. Kokybinio tyrimo rezultatai, kuriais remiamasi straipsnyje, rodo, kad NVO samprata yra neaiški ne tik patiems NVO dalyviams, bet ir valdžios institucijų bei verslo atstovams. NVO dalyvavimas rinkoje tampa problemiškas dėl NVO sampratos ir veikimo lauko kompleksiškumo. Galima teigti, kad NVO socialinio ir ekonominio matmens suderinamumas tampa tam tikru iššūkiu ir dabartinės Lietuvos gerovės valstybės raidai, nes susijęs su NVO sektoriaus išlikimo klausimu.
To address global energy demand, major efforts have been made to develop cutting-edge electrode materials for electrochemical energy storage (EES) devices. The present article discusses the ...hydrothermal synthesis of bare nickel vanadate and a nickel vanadate/reduced graphene oxide (Ni3V2O8-rGO) composite for supercapacitor applications. The physicochemical properties of pure Ni3V2O8 (NVO) and the Ni3V2O8-rGO (NVO-rGO) composite were investigated using a variety of characterization tools. The electrochemical traits of the NVO-rGO composite outperform bare NVO due to the synergistic effect. At a current density of 1 mAcm−2, the NVO and NVO-rGO nanostructures exhibit excellent specific capacitances of 85 Fg−1 and 108 Fg−1, respectively. These nanostructures also have energy densities of about 3.82 and 5.02 WhKg−1, with power densities of 141.75 and 151.57 WKg−1 for NVO and NVO-rGO composite, respectively. Electrochemical impedance spectroscopy (EIS) studies revealed a charge resistance of 2.05 Ω. The transfer coefficient and standard rate constant indicate that the charge storage mechanism is based on a quasi-reversible redox process. The present investigation demonstrates that the NVO-rGO composite has exceptional electrochemical performance. The outstanding electrochemical performance of both NVO and NVO-rGO underlines their potential as novel and promising materials for supercapacitor applications, implying significant feasibility for large-scale utilization.
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Native vertebral osteomyelitis (NVO) caused by Staphylococcus aureus is associated with high risk of treatment failure and increased morbidity. The role of rifampin-based therapy for the treatment of ...this condition is controversial. The goal of this systematic review and meta-analysis is to explore the efficacy and safety of rifampin-based therapy for the treatment of S. aureus NVO.
We searched Cochrane, Embase, Medline, Scopus, and Web of Science databases for studies published up to May 2023, focusing on adults with NVO treated with or without rifampin-containing regimens. A random-effects model meta-analysis estimated relative risks and risk difference with 95% confidence intervals (CI).
Thirteen studies (2 randomized controlled trials and 11 comparative cohort studies), comprising 244 patients with S. aureus NVO who received rifampin and 435 who did not, were analyzed. Meta-analysis showed that rifampin-based regimens were associated with lower risk of clinical failure (risk difference, -14%; 95% CI, -19% to -8%; P < .001; I2 = 0%; relative risk, 0.58; 95% CI, .37-.92, P = .02, I2 = 21%). Only 1 study reported on adverse events. All studies had a high or uncertain risk of bias, and the certainty of evidence was rated as very low.
Adjunctive rifampin therapy might be associated with lower risk of S. aureus NVO treatment failure; however, the low certainty of evidence precludes drawing definitive conclusions that would alter clinical practice. A randomized trial is necessary to corroborate these findings.
Aqueous rechargeable Lithium ion batteries (ARLBs) are considered as the safest alternatives to match the performance of current Li-ion energy storage devices. Herein, we report the configuration of ...a full cell ARLB with Na1.16V3O8 crystalline rods and LiMn2O4 as electrodes that deliver high efficiency and excellent rate performance. In this study Na1.16V3O8 crystalline rods synthesized by one step hydrothermal method were used as the anode and solid microspheres of LiMn2O4 synthesized by a sol–gel synthesis followed by a heat-treatment using LiOH were used as the cathode. The performance of this fabricated full cell was optimized to operate between 0V to 2.3V in aqueous electrolytes to deliver an energy density of ~240Wh/kg that was found to be better than most of the current lithium ion batteries which are based on non-flammable electrolytes. The device fabricated in this study exhibits a round trip efficiency of ~50% at the end of 100cycles with a current density of 500mAg−1. Furthermore, the charge storage mechanism in Na1.16V3O8 rods was also studied to corroborate its suitability as a potential anode material for aqueous rechargeable lithium ion batteries.
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•A cost effective aqueous rechargeable battery for application in wearable electronics•A unique belt like morphology of the anode material to enhance the electrochemical performance of the device•A high specific capacity (~240Whg−1) with round trip efficiency of >50% after 100cycles
In this work, the effects of thermal and compositional stratification on the ignition and burn duration of homogeneous charge compression ignition (HCCI) combustion are studied with full-cycle 3D ...computational fluid dynamics (CFD) simulations with gasoline chemical kinetics performed during the closed portion of the cycle, from intake valve closing (IVC). The stratification was varied through the use of negative valve overlap (NVO) and positive valve overlap (PVO) breathing strategies. To remove charge energy and phasing effects from the simulation results, the fuel mass and ignition timing were held constant, while mean composition effects were isolated from those of local stratification by maintaining the same mean oxygen concentration, fuel–oxygen equivalence ratio and charge heat capacity. Fuel was premixed with the intake to avoid potential stratification effects arising from direct injection. With NVO, the incomplete mixing of the fresh charge with the large mass fraction of product gases retained within the cylinder from the previous combustion cycle leads to a 23% increase in the pre-ignition thermal stratification, and an order of magnitude increase in the levels of stratifications in fuel to oxygen equivalence ratio and oxygen mole fraction relative to the PVO strategy, which employs a premixed mixture of fresh and product gases. Under the conditions studied, the use of NVO resulted in a 30% increase in the 10–90% burn duration (CA10-90) compared to the PVO condition. Two additional analyses were performed to decouple the effects of thermal and compositional stratification. The first examined the reaction space (based on the ignition delay distribution within the charge prior to ignition) for both breathing strategies to quantify the inherent reactivity stratification. The second examined the more stratified NVO case with a quasi-dimensional multi-zone model. These analyses revealed that under the conditions studied, HCCI reactivity and combustion duration are governed primarily by thermal stratification and are largely insensitive to compositional stratification at the time of ignition.
In order to control combustion phasing and extend operation range of homogeneous charged compression ignition (HCCI) engines, several techniques such as controlling inlet air temperature and ...pressure, using alternative fuels, variable compression ratio, supercharging, etc. have been applied. Among them, variable valve mechanism received much attention to extend HCCI operating range and control autoignition. Mode switching between spark plug ignition (SI) to HCCI has been started to use widely because of limited operation range of the HCCI mode. To control of an engine switching combustion modes between SI and HCCI, embedded system needs parametrical control maps of the engine. In this study, operation range, air excess ratio, torque and thermal efficiency maps of an HCCI engine using negative valve overlap (NVO) strategy were obtained and additionally the effects of NVO on HCCI combustion in view of in-cylinder temperature, heat release rate, effective thermal efficiency, combustion phasing, and exhaust emissions were investigated. Also, variation of CO, HC, and NOx emissions were evaluated at different valve overlaps. Three different valve overlap including +8, −8, and −16 CA were used in the experiments. Test results showed that in-cylinder pressure and heat release decreased with NVO. The test engine could run without knocking by application of NVO. It was seen that operating range of HCCI extended with NVO. It was also found that effective thermal efficiency increased with −16ºCA valve overlap compared to other valve timings.
Straipsnio tikslas – remiantis apsibrėžta teorine inovatyvumo koncepcija išanalizuoti, kaip nevyriausybinės organizacijos, dirbančios socialinių paslaugų srityje, vertina savo inovatyvumą. Straipsnio ...įvadinėje dalyje analizuojama inovacijų samprata, aptariami technologinių, vadybinių ir socialinių inovacijų skirtumai, metodinėje dalyje aptariami organizacijų savęs vertinimo metodo ypatumai. Empirinio tyrimo rezultatų dalyje aptariama, kaip pačios NVO vertina savo inovatyvumą, kokias inovacijas jos kuria ir kokius veiksnius mano esant svarbiausius inovacijoms kurti.
Straipsnyje nagrinėjama neįgaliųjų nevyriausybinių organizacijų (NVO) veiklos plėtotė socialinės integracijos kontekste. Aptariama NVO neįgaliųjų socialinė integracija, pateikiant mokslininkų ...teoretikų ir praktikų įvairias socialinės integracijos sampratas. Pristatomas empirinis tyrimas, kuriuo siekta atskleisti tiriamųjų požiūrį į NVO veiklos plėtotę ir patirtį. Straipsnio autorės atlikto kokybinio tyrimo rezultatai atskleidė, kad neįgaliųjų socioedukaciniai poreikiai NVO tenkinami ir atstovaujama NVO veiklos forma yra grupinė. Tyrimo rezultatai parodė, kad NVO administracija patiria iššūkių, tai valdžios institucijų atstovų biurokratizmas NVO atžvilgiu ir žinojimo apie neįgaliuosius stoką. Atskleidžiami socialinės integracijos veiksniai, lemiantys NVO veiklos plėtotės pokyčius. Remiantis kokybinio tyrimo rezultatais paaiškėjo, kad sėkminga neįgaliųjų socialinė integracija yra interesų atstovavimas, orientuotas į neįgaliųjų aktyvumą, NVO patiems darant įtaką valdžios sprendimams ir pačių neįgaliųjų gebėjimas kooperuotis NVO veikloje.
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