In the rapidly evolving field of cybersecurity,the challenge of providing realistic exercise scenarios that accurately mimic real-world threats has become increasingly critical.Traditional methods often fall short in ...In the rapidly evolving field of cybersecurity,the challenge of providing realistic exercise scenarios that accurately mimic real-world threats has become increasingly critical.Traditional methods often fall short in capturing the dynamic and complex nature of modern cyber threats.To address this gap,we propose a comprehensive framework designed to create authentic network environments tailored for cybersecurity exercise systems.Our framework leverages advanced simulation techniques to generate scenarios that mirror actual network conditions faced by professionals in the field.The cornerstone of our approach is the use of a conditional tabular generative adversarial network(CTGAN),a sophisticated tool that synthesizes realistic synthetic network traffic by learning fromreal data patterns.This technology allows us to handle technical components and sensitive information with high fidelity,ensuring that the synthetic data maintains statistical characteristics similar to those observed in real network environments.By meticulously analyzing the data collected from various network layers and translating these into structured tabular formats,our framework can generate network traffic that closely resembles that found in actual scenarios.An integral part of our process involves deploying this synthetic data within a simulated network environment,structured on software-defined networking(SDN)principles,to test and refine the traffic patterns.This simulation not only facilitates a direct comparison between the synthetic and real traffic but also enables us to identify discrepancies and refine the accuracy of our simulations.Our initial findings indicate an error rate of approximately 29.28%between the synthetic and real traffic data,highlighting areas for further improvement and adjustment.By providing a diverse array of network scenarios through our framework,we aim to enhance the exercise systems used by cybersecurity professionals.This not only improves their ability to respond to actual cyber threats but also ensures that the exercise is cost-effective and efficient.展开更多
Ni-based porous electrocatalysts have been widely used in the hydrogen evolution reaction(HER)in alkaline water electrolysis,and the catalysts are produced by selective leaching of Al from Ni-Al alloys.It is well know...Ni-based porous electrocatalysts have been widely used in the hydrogen evolution reaction(HER)in alkaline water electrolysis,and the catalysts are produced by selective leaching of Al from Ni-Al alloys.It is well known that chemical leaching of Ni-Al intermetallic compound(IMC)generates a high surface area in Ni(OH)_(2).However,the Ni(OH)_(2) produced by leaching the Ni-Al intermetallic compound retards the hydrogen evolution reaction,which is attributed to its weak hydrogen adsorption energy.In this study,we controlled the chemical state of Ni using plasma vapor deposition(PVD)followed by heat treatment,selective Al leaching,and electrochemical reduction.X-ray diffraction(XRD),scanning microscopy(SEM),transmission electron microscopy(TEM),and energy-dispersive X-ray spectroscopy(EDS)were used to confirm the phase evolution of the electrocatalysts during fabrication.We reveal that the heat-treated Ni-Al alloy with a thick Ni2Al3surface layer underwent selective Al leaching and produced biphasic interfaces comprising Ni(OH)_(2) and NiAl IMCs at the edges of the grains in the outermost surface layer.Coupled oxidation of the interfacing NiAl IMCs facilitated the partial reduction of Ni(OH)_(2) to Ni(OH)_(2)/Ni in the grains during electrochemical reduction,as confirmed by X-ray photoelectron spectroscopy(XPS).An electrocatalyst containing partially reduced Ni(OH)_(2)/Ni exhibited an overpotential of 54 mV at 10 mA/cm^(2) in a half-cell measurement,and a cell voltage of 1.675 V at 0.4 A/cm2for single-cell operation.A combined experimental and theoretical study(density functional theory calculations)revealed that the superior HER activity was attributed to the presence of partially reduced metallic Ni with various defects and residual Al,which facilitated water adsorption,dissociation,and finally hydrogen evolution.展开更多
A split gate MOSFET(SG-MOSFET)is widely known for reducing the reverse transfer capacitance(C_(RSS)).In a 3.3 kV class,the SG-MOSFET does not provide reliable operation due to the high gate oxide electric field.In add...A split gate MOSFET(SG-MOSFET)is widely known for reducing the reverse transfer capacitance(C_(RSS)).In a 3.3 kV class,the SG-MOSFET does not provide reliable operation due to the high gate oxide electric field.In addition to the poor static performance,the SG-MOSFET has issues such as the punch through and drain-induced barrier lowering(DIBL)caused by the high gate oxide electric field.As such,a 3.3 kV 4 H-SiC split gate MOSFET with a grounded central implant region(SG-CIMOSFET)is proposed to resolve these issues and for achieving a superior trade-off between the static and switching performance.The SG-CIMOSFET has a significantly low on-resistance(R_(ON))and maximum gate oxide field(E_(OX))due to the central implant region.A grounded central implant region significantly reduces the C_(RSS)and gate drain charge(Q_(GD))by partially screening the gate-to-drain capacitive coupling.Compared to a planar MOSFET,the SG MOSFET,central implant MOSFET(CIMOSFET),the SGCIMOSFET improve the R_(ON)×Q_(GD)by 83.7%,72.4%and 44.5%,respectively.The results show that the device features not only the smallest switching energy loss but also the fastest switching time.展开更多
In this paper,a 4 H-Si C DMOSFET with a source-contacted dummy gate(DG-MOSFET)is proposed and analyzed through Sentaurus TCAD and PSIM simulations.The source-contacted MOS structure forms fewer depletion regions than ...In this paper,a 4 H-Si C DMOSFET with a source-contacted dummy gate(DG-MOSFET)is proposed and analyzed through Sentaurus TCAD and PSIM simulations.The source-contacted MOS structure forms fewer depletion regions than the PN junction.Therefore,the overlapping region between the gate and the drain can be significantly reduced while limiting RON degradation.As a result,the DG-MOSFET offers an improved high-frequency figure of merit(HF-FOM)over the conventional DMOSFET(C-MOSFET)and central-implant MOSFET(CI-MOSFET).The HF-FOM(RON×QGD)of the DG-MOSFET was improved by59.2%and 22.2%compared with those of the C-MOSFET and CI-MOSFET,respectively.In a double-pulse test,the DG-MOSFET could save total power losses of 53.4%and 5.51%,respectively.Moreover,in a power circuit simulation,the switching power loss was reduced by 61.9%and 12.7%in a buck converter and 61%and 9.6%in a boost converter.展开更多
The cross sections of the ^(59)Co(n,x)reaction in the average energy range of 15.2-37.2 MeV were meas-ured using activation and an off-line γ-ray spectrometric technique.The neutrons were generated from the ^(9)Be(p,...The cross sections of the ^(59)Co(n,x)reaction in the average energy range of 15.2-37.2 MeV were meas-ured using activation and an off-line γ-ray spectrometric technique.The neutrons were generated from the ^(9)Be(p,n)reaction with proton beam energies of 25-45 MeV at the MC-50 Cyclotron facility of the Korean Institute of Radi-ological and Medical Sciences(KIRAMS).Theoretical cal lculations of neutron-induced reactions on ^(59)Co were per-formed using the nuclear model code TALYS-1.9.The results for the ^(59)Co(n,x)reactions were compared with the theoretical values obtained using TALYS-1.9 and the literature data provided in EXFOR and the TENDL 2019 nuc-lear data library.The theoretical values obtained using TALYS-1.9 with adjusted parameters are comparable to the experimental data.The measured reaction cross sections of a few radionuclides are new,and the others are compar-able to the literature data,and thus,they can strengthen the database.The present study on cross sections leads to useful insight into the mechanisms of ^(59)Co(n,x)reactions.展开更多
基金supported in part by the Korea Research Institute for Defense Technology Planning and Advancement(KRIT)funded by the Korean Government’s Defense Acquisition Program Administration(DAPA)under Grant KRIT-CT-21-037in part by the Ministry of Education,Republic of Koreain part by the National Research Foundation of Korea under Grant RS-2023-00211871.
文摘In the rapidly evolving field of cybersecurity,the challenge of providing realistic exercise scenarios that accurately mimic real-world threats has become increasingly critical.Traditional methods often fall short in capturing the dynamic and complex nature of modern cyber threats.To address this gap,we propose a comprehensive framework designed to create authentic network environments tailored for cybersecurity exercise systems.Our framework leverages advanced simulation techniques to generate scenarios that mirror actual network conditions faced by professionals in the field.The cornerstone of our approach is the use of a conditional tabular generative adversarial network(CTGAN),a sophisticated tool that synthesizes realistic synthetic network traffic by learning fromreal data patterns.This technology allows us to handle technical components and sensitive information with high fidelity,ensuring that the synthetic data maintains statistical characteristics similar to those observed in real network environments.By meticulously analyzing the data collected from various network layers and translating these into structured tabular formats,our framework can generate network traffic that closely resembles that found in actual scenarios.An integral part of our process involves deploying this synthetic data within a simulated network environment,structured on software-defined networking(SDN)principles,to test and refine the traffic patterns.This simulation not only facilitates a direct comparison between the synthetic and real traffic but also enables us to identify discrepancies and refine the accuracy of our simulations.Our initial findings indicate an error rate of approximately 29.28%between the synthetic and real traffic data,highlighting areas for further improvement and adjustment.By providing a diverse array of network scenarios through our framework,we aim to enhance the exercise systems used by cybersecurity professionals.This not only improves their ability to respond to actual cyber threats but also ensures that the exercise is cost-effective and efficient.
基金supported by a Korea Evaluation Institute of Industrial Technology(KEIT)grant funded by the Korean government(MOTIE)(No.20022449)Commercialization Promotion Agency for R&D Outcomes(COMPA)grant funded by the Korean government(MSIT)(No.2021E100)+1 种基金supported by the Korea Electric Power Corporation(KEPCO),Open R&D(R22X004)the National Institute of Supercomputing and Network/Korea Institute of Science and Technology Information,which provided supercomputing resources,including technical support(KSC-2021-CRE-0568)。
文摘Ni-based porous electrocatalysts have been widely used in the hydrogen evolution reaction(HER)in alkaline water electrolysis,and the catalysts are produced by selective leaching of Al from Ni-Al alloys.It is well known that chemical leaching of Ni-Al intermetallic compound(IMC)generates a high surface area in Ni(OH)_(2).However,the Ni(OH)_(2) produced by leaching the Ni-Al intermetallic compound retards the hydrogen evolution reaction,which is attributed to its weak hydrogen adsorption energy.In this study,we controlled the chemical state of Ni using plasma vapor deposition(PVD)followed by heat treatment,selective Al leaching,and electrochemical reduction.X-ray diffraction(XRD),scanning microscopy(SEM),transmission electron microscopy(TEM),and energy-dispersive X-ray spectroscopy(EDS)were used to confirm the phase evolution of the electrocatalysts during fabrication.We reveal that the heat-treated Ni-Al alloy with a thick Ni2Al3surface layer underwent selective Al leaching and produced biphasic interfaces comprising Ni(OH)_(2) and NiAl IMCs at the edges of the grains in the outermost surface layer.Coupled oxidation of the interfacing NiAl IMCs facilitated the partial reduction of Ni(OH)_(2) to Ni(OH)_(2)/Ni in the grains during electrochemical reduction,as confirmed by X-ray photoelectron spectroscopy(XPS).An electrocatalyst containing partially reduced Ni(OH)_(2)/Ni exhibited an overpotential of 54 mV at 10 mA/cm^(2) in a half-cell measurement,and a cell voltage of 1.675 V at 0.4 A/cm2for single-cell operation.A combined experimental and theoretical study(density functional theory calculations)revealed that the superior HER activity was attributed to the presence of partially reduced metallic Ni with various defects and residual Al,which facilitated water adsorption,dissociation,and finally hydrogen evolution.
基金supported by the MSIT(Ministry of Science and ICT),Korea,under the ITRC(Information Technology Research Center)support program(IITP-2020-2018-0-01421)supervised by the IITP(Institute for Information&communications Technology Promotion)then Samsung Electronics.
文摘A split gate MOSFET(SG-MOSFET)is widely known for reducing the reverse transfer capacitance(C_(RSS)).In a 3.3 kV class,the SG-MOSFET does not provide reliable operation due to the high gate oxide electric field.In addition to the poor static performance,the SG-MOSFET has issues such as the punch through and drain-induced barrier lowering(DIBL)caused by the high gate oxide electric field.As such,a 3.3 kV 4 H-SiC split gate MOSFET with a grounded central implant region(SG-CIMOSFET)is proposed to resolve these issues and for achieving a superior trade-off between the static and switching performance.The SG-CIMOSFET has a significantly low on-resistance(R_(ON))and maximum gate oxide field(E_(OX))due to the central implant region.A grounded central implant region significantly reduces the C_(RSS)and gate drain charge(Q_(GD))by partially screening the gate-to-drain capacitive coupling.Compared to a planar MOSFET,the SG MOSFET,central implant MOSFET(CIMOSFET),the SGCIMOSFET improve the R_(ON)×Q_(GD)by 83.7%,72.4%and 44.5%,respectively.The results show that the device features not only the smallest switching energy loss but also the fastest switching time.
基金supported by the MSIT(Ministry of Science and ICT),Korea,under the ITRC(Information Technology Research Center)support program(IITP-2020-2018-0-01421)supervised by the IITP(Institute for Information&Communications Technology Planning&Evaluation)。
文摘In this paper,a 4 H-Si C DMOSFET with a source-contacted dummy gate(DG-MOSFET)is proposed and analyzed through Sentaurus TCAD and PSIM simulations.The source-contacted MOS structure forms fewer depletion regions than the PN junction.Therefore,the overlapping region between the gate and the drain can be significantly reduced while limiting RON degradation.As a result,the DG-MOSFET offers an improved high-frequency figure of merit(HF-FOM)over the conventional DMOSFET(C-MOSFET)and central-implant MOSFET(CI-MOSFET).The HF-FOM(RON×QGD)of the DG-MOSFET was improved by59.2%and 22.2%compared with those of the C-MOSFET and CI-MOSFET,respectively.In a double-pulse test,the DG-MOSFET could save total power losses of 53.4%and 5.51%,respectively.Moreover,in a power circuit simulation,the switching power loss was reduced by 61.9%and 12.7%in a buck converter and 61%and 9.6%in a boost converter.
基金National Research Foundation of Korea(NRF)through a grant provided by the Ministry of Science and ICT(NRF-2017R ID1A1B03030484,NRF-2013M7A1A1075764,NRF-2018R1A6A1A06024970)。
文摘The cross sections of the ^(59)Co(n,x)reaction in the average energy range of 15.2-37.2 MeV were meas-ured using activation and an off-line γ-ray spectrometric technique.The neutrons were generated from the ^(9)Be(p,n)reaction with proton beam energies of 25-45 MeV at the MC-50 Cyclotron facility of the Korean Institute of Radi-ological and Medical Sciences(KIRAMS).Theoretical cal lculations of neutron-induced reactions on ^(59)Co were per-formed using the nuclear model code TALYS-1.9.The results for the ^(59)Co(n,x)reactions were compared with the theoretical values obtained using TALYS-1.9 and the literature data provided in EXFOR and the TENDL 2019 nuc-lear data library.The theoretical values obtained using TALYS-1.9 with adjusted parameters are comparable to the experimental data.The measured reaction cross sections of a few radionuclides are new,and the others are compar-able to the literature data,and thus,they can strengthen the database.The present study on cross sections leads to useful insight into the mechanisms of ^(59)Co(n,x)reactions.