As data analysis often incurs significant communication and computational costs,these tasks are increasingly outsourced to cloud computing platforms.However,this introduces privacy concerns,as sensitive data must be t...As data analysis often incurs significant communication and computational costs,these tasks are increasingly outsourced to cloud computing platforms.However,this introduces privacy concerns,as sensitive data must be transmitted to and processed by untrusted parties.To address this,fully homomorphic encryption(FHE)has emerged as a promising solution for privacy-preserving Machine-Learning-as-a-Service(MLaaS),enabling computation on encrypted data without revealing the plaintext.Nevertheless,FHE remains computationally expensive.As a result,approximate homomorphic encryption(AHE)schemes,such as CKKS,have attracted attention due to their efficiency.In our previous work,we proposed RP-OKC,a CKKS-based clustering scheme implemented via TenSEAL.However,errors inherent to CKKS operations—termed CKKS-errors—can affect the accuracy of the result after decryption.Since these errors can be mitigated through post-decryption rounding,we propose a data pre-scaling technique to increase the number of significant digits and reduce CKKS-errors.Furthermore,we introduce an Operation-Error-Estimation(OEE)table that quantifies upper-bound error estimates for various CKKS operations.This table enables error-aware decryption correction,ensuring alignment between encrypted and plaintext results.We validate our method on K-means clustering using the Kaggle Customer Segmentation dataset.Experimental results confirm that the proposed scheme enhances the accuracy and reliability of privacy-preserving data analysis in cloud environments.展开更多
To improve the characteristics of a diamond-like carbon （DLC） film, Ti-containing amorphous hydrogenated carbon thin films were deposited on sus304 stainless steel substrates by high-power plasma-sputtering with tit...To improve the characteristics of a diamond-like carbon （DLC） film, Ti-containing amorphous hydrogenated carbon thin films were deposited on sus304 stainless steel substrates by high-power plasma-sputtering with titanium metal as the solid plasma source in a mixed ArC2H2 atmosphere. The films were fabricated to obtain a multilayered structure of Ti/TiC/DLC gradient for improving adhesion and reducing residual stress. The effects of substrate bias and target-substrate distance on the films＇ properties were studied by glow discharge spectroscope, X-ray diffractometer, Raman spectroscope, nanoindenter, and a pin-on-disk tribometer. The results indicate that the films possess superior adhesive strength and toughness.展开更多
In this paper, we present the study of system dynamics of the floating kuroshio turbine（FKT） system which is designed to harness ocean current energy. We focus on the mooring line system design and its interaction w...In this paper, we present the study of system dynamics of the floating kuroshio turbine（FKT） system which is designed to harness ocean current energy. We focus on the mooring line system design and its interaction with the FKT system. The effects of line diameter and two different auxiliary line systems were studied. Their responses in waves were also investigated. We integrated several commercial and in-house packages. The system buoyancy and weight and their centers were estimated using the Rhino software. The system hydrodynamic coefficients were obtained through WAMIT, system drag coefficient through FLUENT, turbine propulsive force through lifting surface code, and system dynamics through Orca Flex. The results show that the mooring line system can create strong influence on the FKT system operations in the ocean current environments.展开更多
We apply in this study an area preserving level set method to simulate gas/water interface flow.For the sake of accuracy,the spatial derivative terms in the equations of motion for an incompressible fluid flow are app...We apply in this study an area preserving level set method to simulate gas/water interface flow.For the sake of accuracy,the spatial derivative terms in the equations of motion for an incompressible fluid flow are approximated by the fifthorder accurate upwinding combined compact difference(UCCD)scheme.This scheme development employs two coupled equations to calculate the first-and second-order derivative terms in the momentum equations.For accurately predicting the level set value,the interface tracking scheme is also developed to minimize phase error of the first-order derivative term shown in the pure advection equation.For the purpose of retaining the long-term accurate Hamiltonian in the advection equation for the level set function,the time derivative term is discretized by the sixth-order accurate symplectic Runge-Kutta scheme.Also,to keep as a distance function for ensuring the front having a finite thickness for all time,the re-initialization equation is used.For the verification of the optimized UCCD scheme for the pure advection equation,two benchmark problems have been chosen to investigate in this study.The level set method with excellent area conservation property proposed for capturing the interface in incompressible fluid flows is also verified by solving the dam-break,Rayleigh-Taylor instability,two-bubble rising in water,and droplet falling problems.展开更多
In this paper an explicit finite-difference time-domain scheme for solving the Maxwell’s equations in non-staggered grids is presented.The proposed scheme for solving the Faraday’s and Amp`ere’s equations in a theo...In this paper an explicit finite-difference time-domain scheme for solving the Maxwell’s equations in non-staggered grids is presented.The proposed scheme for solving the Faraday’s and Amp`ere’s equations in a theoretical manner is aimed to preserve discrete zero-divergence for the electric and magnetic fields.The inherent local conservation laws in Maxwell’s equations are also preserved discretely all the time using the explicit second-order accurate symplectic partitioned Runge-Kutta scheme.The remaining spatial derivative terms in the semi-discretized Faraday’s and Amp`ere’s equations are then discretized to provide an accurate mathematical dispersion relation equation that governs the numerical angular frequency and the wavenumbers in two space dimensions.To achieve the goal of getting the best dispersive characteristics,we propose a fourth-order accurate space centered scheme which minimizes the difference between the exact and numerical dispersion relation equations.Through the computational exercises,the proposed dual-preserving solver is computationally demonstrated to be efficient for use to predict the long-term accurate Maxwell’s solutions.展开更多
This study introduces a novel image capture and lighting techniques using a cutting-edge hybrid MEMS scanner system designed for compact microscopic imaging.The scanner comprises a tapered optical fiber waveguide and ...This study introduces a novel image capture and lighting techniques using a cutting-edge hybrid MEMS scanner system designed for compact microscopic imaging.The scanner comprises a tapered optical fiber waveguide and innovative aerosol-jet printed PZT(lead zirconate titanate)bimorph push-pull actuators on a stainless-steel substrate,effectively addressing issues that are commonly associated with PZT on silicon substrates such as fracture and layer separation.By leveraging nonlinear vibration,the scanner achieves a spiral scan pattern from a single signal input,in addition to the expected two-dimensional scanning and target illumination from two phase-shifted inputs.This capability is further enhanced by a novel process to taper the optical fiber,which reduces illumination scattering and tunes the fiber to the resonant frequencies of the scanner.The precisely tapered tip enables large fields of view while maintaining independent 2-axis scanning through one-degree-of-freedom actuation.Experimental validation showcases the successful generation of a spiral scan pattern with a 60μm diameter scan area and a 10 Hz frame rate,effectively reconstructing scanned images of 5μm lines,cross patterns(15μm in length with a 5μm gap),and structures of a Psychodidae wing.展开更多
基金funded by National Science and Technology Council,Taiwan,grant numbers are 110-2401-H-002-094-MY2 and 112-2221-E-130-001.
文摘As data analysis often incurs significant communication and computational costs,these tasks are increasingly outsourced to cloud computing platforms.However,this introduces privacy concerns,as sensitive data must be transmitted to and processed by untrusted parties.To address this,fully homomorphic encryption(FHE)has emerged as a promising solution for privacy-preserving Machine-Learning-as-a-Service(MLaaS),enabling computation on encrypted data without revealing the plaintext.Nevertheless,FHE remains computationally expensive.As a result,approximate homomorphic encryption(AHE)schemes,such as CKKS,have attracted attention due to their efficiency.In our previous work,we proposed RP-OKC,a CKKS-based clustering scheme implemented via TenSEAL.However,errors inherent to CKKS operations—termed CKKS-errors—can affect the accuracy of the result after decryption.Since these errors can be mitigated through post-decryption rounding,we propose a data pre-scaling technique to increase the number of significant digits and reduce CKKS-errors.Furthermore,we introduce an Operation-Error-Estimation(OEE)table that quantifies upper-bound error estimates for various CKKS operations.This table enables error-aware decryption correction,ensuring alignment between encrypted and plaintext results.We validate our method on K-means clustering using the Kaggle Customer Segmentation dataset.Experimental results confirm that the proposed scheme enhances the accuracy and reliability of privacy-preserving data analysis in cloud environments.
文摘To improve the characteristics of a diamond-like carbon （DLC） film, Ti-containing amorphous hydrogenated carbon thin films were deposited on sus304 stainless steel substrates by high-power plasma-sputtering with titanium metal as the solid plasma source in a mixed ArC2H2 atmosphere. The films were fabricated to obtain a multilayered structure of Ti/TiC/DLC gradient for improving adhesion and reducing residual stress. The effects of substrate bias and target-substrate distance on the films＇ properties were studied by glow discharge spectroscope, X-ray diffractometer, Raman spectroscope, nanoindenter, and a pin-on-disk tribometer. The results indicate that the films possess superior adhesive strength and toughness.
基金the grant from Ministry of Science and Technology, the Republic of China, under the contract MOST 105-3113-E-002019-CC2 and funding support from CSBC Corporation
文摘In this paper, we present the study of system dynamics of the floating kuroshio turbine（FKT） system which is designed to harness ocean current energy. We focus on the mooring line system design and its interaction with the FKT system. The effects of line diameter and two different auxiliary line systems were studied. Their responses in waves were also investigated. We integrated several commercial and in-house packages. The system buoyancy and weight and their centers were estimated using the Rhino software. The system hydrodynamic coefficients were obtained through WAMIT, system drag coefficient through FLUENT, turbine propulsive force through lifting surface code, and system dynamics through Orca Flex. The results show that the mooring line system can create strong influence on the FKT system operations in the ocean current environments.
基金This work was supported by the National Science Council of Republic of China under the Grants NSC-94-2611-E-002-021,NSC-94-2745-P-002-002 and CQSE project 97R0066-69.
文摘We apply in this study an area preserving level set method to simulate gas/water interface flow.For the sake of accuracy,the spatial derivative terms in the equations of motion for an incompressible fluid flow are approximated by the fifthorder accurate upwinding combined compact difference(UCCD)scheme.This scheme development employs two coupled equations to calculate the first-and second-order derivative terms in the momentum equations.For accurately predicting the level set value,the interface tracking scheme is also developed to minimize phase error of the first-order derivative term shown in the pure advection equation.For the purpose of retaining the long-term accurate Hamiltonian in the advection equation for the level set function,the time derivative term is discretized by the sixth-order accurate symplectic Runge-Kutta scheme.Also,to keep as a distance function for ensuring the front having a finite thickness for all time,the re-initialization equation is used.For the verification of the optimized UCCD scheme for the pure advection equation,two benchmark problems have been chosen to investigate in this study.The level set method with excellent area conservation property proposed for capturing the interface in incompressible fluid flows is also verified by solving the dam-break,Rayleigh-Taylor instability,two-bubble rising in water,and droplet falling problems.
基金supported by the National Science Council of the Republic of China under the Grants NSC96-2221-E-002-293-MY2,NSC96-2221-E-002-004,and CQSE97R0066-69.
文摘In this paper an explicit finite-difference time-domain scheme for solving the Maxwell’s equations in non-staggered grids is presented.The proposed scheme for solving the Faraday’s and Amp`ere’s equations in a theoretical manner is aimed to preserve discrete zero-divergence for the electric and magnetic fields.The inherent local conservation laws in Maxwell’s equations are also preserved discretely all the time using the explicit second-order accurate symplectic partitioned Runge-Kutta scheme.The remaining spatial derivative terms in the semi-discretized Faraday’s and Amp`ere’s equations are then discretized to provide an accurate mathematical dispersion relation equation that governs the numerical angular frequency and the wavenumbers in two space dimensions.To achieve the goal of getting the best dispersive characteristics,we propose a fourth-order accurate space centered scheme which minimizes the difference between the exact and numerical dispersion relation equations.Through the computational exercises,the proposed dual-preserving solver is computationally demonstrated to be efficient for use to predict the long-term accurate Maxwell’s solutions.
基金funded by the Ministry of Science and Technology,Taiwan,China(MOST 104-2218-E-007-026-MY3,MOST 107-2221-E-007-054-MY3,MOST 110-2221-E-007-069,and MOST 111-2221-E-007-101).
文摘This study introduces a novel image capture and lighting techniques using a cutting-edge hybrid MEMS scanner system designed for compact microscopic imaging.The scanner comprises a tapered optical fiber waveguide and innovative aerosol-jet printed PZT(lead zirconate titanate)bimorph push-pull actuators on a stainless-steel substrate,effectively addressing issues that are commonly associated with PZT on silicon substrates such as fracture and layer separation.By leveraging nonlinear vibration,the scanner achieves a spiral scan pattern from a single signal input,in addition to the expected two-dimensional scanning and target illumination from two phase-shifted inputs.This capability is further enhanced by a novel process to taper the optical fiber,which reduces illumination scattering and tunes the fiber to the resonant frequencies of the scanner.The precisely tapered tip enables large fields of view while maintaining independent 2-axis scanning through one-degree-of-freedom actuation.Experimental validation showcases the successful generation of a spiral scan pattern with a 60μm diameter scan area and a 10 Hz frame rate,effectively reconstructing scanned images of 5μm lines,cross patterns(15μm in length with a 5μm gap),and structures of a Psychodidae wing.
